diff --git a/biome.json b/biome.json
index 7f0377a0..20ba54c3 100644
--- a/biome.json
+++ b/biome.json
@@ -14,7 +14,8 @@
         "rules": {
             "recommended": true,
             "correctness": {
-                "noUnusedVariables": "warn"
+                "noUnusedVariables": "warn",
+                "noUndeclaredVariables": "error"
             },
             "style": {
                 "noDescendingSpecificity": "off"
diff --git a/build.rs b/build.rs
index 6dfbb442..d653cc82 100644
--- a/build.rs
+++ b/build.rs
@@ -113,15 +113,19 @@ fn process_release(manifest_dir: &Path, static_dir: &Path, out_dir: &Path) {
     // ── 4. Minify ALL individual CSS in static-dist/ ─────────────────────────
     minify_tree_css(&dist_dir.join("css"));
 
-    // ── 5. Build JS bundle for index.html ────────────────────────────────────
+    // ── 5. Bundle all ES modules into one IIFE ───────────────────────────────
+    // Walk the import graph starting from every <script type="module"> in index.html,
+    // strip import/export syntax, wrap in an IIFE, then minify as a classic script.
     let index_html = fs::read_to_string(static_dir.join("index.html")).expect("read index.html");
-    let defer_scripts = extract_defer_scripts(&index_html);
-    let js_bundle = build_js_bundle(static_dir, &defer_scripts);
+    let module_scripts = extract_module_scripts(&index_html);
+    let js_raw = build_js_module_bundle(&module_scripts, static_dir);
+    let js_bundle = js_minify_script_safe(&js_raw);
     let js_hash = fnv_hash(js_bundle.as_bytes());
     let js_name = format!("app.{js_hash}.js");
+    fs::create_dir_all(dist_dir.join("js")).expect("js dir");
     fs::write(dist_dir.join("js").join(&js_name), &js_bundle).expect("write js bundle");
 
-    // ── 6. Minify ALL individual JS in static-dist/ ──────────────────────────
+    // ── 6. Minify ALL individual JS files in static-dist/ ────────────────────
     minify_tree_js(&dist_dir.join("js"));
 
     // ── 7. Inline theme-init.js  &  rewrite index.html ──────────────────────
@@ -246,15 +250,15 @@ fn minify_tree_css(dir: &Path) {
 }
 
 // ═══════════════════════════════════════════════════════════════════════════════
-// JS processing
+// JS bundling (ES module → single IIFE)
 // ═══════════════════════════════════════════════════════════════════════════════
 
-/// Collect `<script defer src="…">` paths from HTML.
-fn extract_defer_scripts(html: &str) -> Vec<String> {
+/// Collect `<script type="module" src="…">` paths from HTML.
+fn extract_module_scripts(html: &str) -> Vec<String> {
     html.lines()
         .filter_map(|l| {
             let t = l.trim();
-            if t.starts_with("<script") && t.contains("defer") && t.contains("src=\"") {
+            if t.starts_with("<script") && t.contains("type=\"module\"") && t.contains("src=\"") {
                 let s = t.find("src=\"")? + 5;
                 let e = t[s..].find('"')? + s;
                 Some(t[s..e].to_string())
@@ -265,35 +269,275 @@ fn extract_defer_scripts(html: &str) -> Vec<String> {
         .collect()
 }
 
-/// Minify each script individually, then concatenate (safer than a monolith parse).
-fn build_js_bundle(static_dir: &Path, script_paths: &[String]) -> String {
-    let mut bundle = String::with_capacity(512 * 1024);
-    for path in script_paths {
-        let file = static_dir.join(path.trim_start_matches('/'));
-        if file.exists() {
-            let src = fs::read_to_string(&file).unwrap_or_default();
-            let min = js_minify_safe(&src);
-            bundle.push_str(&min);
-            bundle.push_str(";\n");
-        } else {
-            eprintln!("cargo:warning=JS not found: {}", file.display());
+/// Build a single IIFE from all ES-module entry points.
+///
+/// Algorithm:
+///   1. DFS from each entry point, following `import … from '…'` edges.
+///   2. Post-order traversal ensures every dependency is emitted before its importer.
+///   3. Cycles are broken by marking files as visited before recursing.
+///   4. Each file has its import/export syntax stripped before being appended.
+///   5. The result is wrapped in `(function(){"use strict"; …})();`.
+fn build_js_module_bundle(entry_scripts: &[String], static_dir: &Path) -> String {
+    use std::collections::HashSet;
+
+    let mut order: Vec<PathBuf> = Vec::new();
+    let mut seen: HashSet<PathBuf> = HashSet::new();
+
+    for script in entry_scripts {
+        let path = static_dir.join(script.trim_start_matches('/'));
+        collect_module_deps(&path, &mut order, &mut seen);
+    }
+
+    let mut bundle = String::with_capacity(2 * 1024 * 1024);
+    bundle.push_str("(function(){\n\"use strict\";\n");
+    for file in &order {
+        match fs::read_to_string(file) {
+            Ok(src) => {
+                bundle.push_str(&strip_esm_syntax(&src));
+                bundle.push('\n');
+            }
+            Err(e) => eprintln!("cargo:warning=bundle: cannot read {}: {e}", file.display()),
         }
     }
+    bundle.push_str("})();\n");
     bundle
 }
 
-/// Minify JS via oxc — returns original on failure.
+/// DFS post-order: push `file` to `order` after all its imports.
+/// Marks files as seen before recursing to break circular dependencies.
+fn collect_module_deps(
+    file: &Path,
+    order: &mut Vec<PathBuf>,
+    seen: &mut std::collections::HashSet<PathBuf>,
+) {
+    let canonical = match file.canonicalize() {
+        Ok(p) => p,
+        Err(_) => {
+            eprintln!("cargo:warning=JS import not found: {}", file.display());
+            return;
+        }
+    };
+    if !seen.insert(canonical.clone()) {
+        return; // already visited (or in-progress cycle)
+    }
+
+    let src = fs::read_to_string(file).unwrap_or_default();
+    let base = file.parent().unwrap_or(Path::new("."));
+
+    for rel in extract_esm_import_paths(&src) {
+        if rel.starts_with('.') {
+            collect_module_deps(&base.join(&rel), order, seen);
+        }
+        // Non-relative (bare specifiers like 'react') are ignored — not used here.
+    }
+
+    order.push(file.to_path_buf());
+}
+
+/// Return all relative paths found in `import … from '…'` / `export … from '…'` lines.
+fn extract_esm_import_paths(source: &str) -> Vec<String> {
+    let mut paths = Vec::new();
+    let mut multiline = false;
+
+    for line in source.lines() {
+        let t = line.trim();
+
+        if multiline {
+            // Waiting for the `from '…'` of a multi-line import
+            if let Some(p) = extract_from_clause(t) {
+                paths.push(p);
+                multiline = false;
+            } else if t.ends_with(';') {
+                multiline = false; // malformed, give up on this import
+            }
+            continue;
+        }
+
+        if !t.starts_with("import ") && !t.starts_with("export ") {
+            continue;
+        }
+
+        if let Some(p) = extract_from_clause(t) {
+            paths.push(p);
+        } else if t.starts_with("import ") && !t.ends_with(';') && !t.contains("//") {
+            // Multi-line: `import {\n  X,\n  Y\n} from '…'`
+            multiline = true;
+        }
+    }
+    paths
+}
+
+/// Extract the path string from the `from '…'` or `from "…"` tail of a line.
+fn extract_from_clause(s: &str) -> Option<String> {
+    let from = s.rfind(" from ")?;
+    let rest = s[from + 6..].trim();
+    let q = rest.chars().next()?;
+    if q != '\'' && q != '"' {
+        return None;
+    }
+    let end = rest[1..].find(q)? + 1;
+    Some(rest[1..end].to_string())
+}
+
+/// Strip ES-module syntax from a single file so it can be inlined into an IIFE.
+///
+/// | Input                                    | Output                       |
+/// |------------------------------------------|------------------------------|
+/// | `import { X } from './y.js';`            | *(empty line)*               |
+/// | `import { X as Y } from './y.js';`       | `const Y = X;`               |
+/// | `export { X, Y };`                       | *(empty line)*               |
+/// | `export { X } from './y.js';`            | *(empty line)*               |
+/// | `export const X = …`                     | `const X = …`                |
+/// | `export function f() {…}`               | `function f() {…}`           |
+/// | `export async function f() {…}`         | `async function f() {…}`     |
+/// | `export class C {…}`                    | `class C {…}`                |
+/// | `export default expr;`                   | `const _default = expr;`     |
+fn strip_esm_syntax(source: &str) -> String {
+    let mut out = String::with_capacity(source.len());
+    // True while we are inside a multi-line import/export-list that has not yet
+    // seen its terminating `;`.
+    let mut skipping = false;
+
+    for line in source.lines() {
+        let t = line.trim();
+
+        if skipping {
+            // Keep skipping until the statement ends
+            if t.ends_with(';') || t.contains(" from ") {
+                skipping = false;
+            }
+            out.push('\n'); // preserve line count for source maps / debugging
+            continue;
+        }
+
+        // ── import … ──────────────────────────────────────────────────────────
+        // Emit `const Y = X;` for any `import { X as Y }` aliases so that code
+        // using the aliased name still resolves inside the IIFE scope.
+        if t.starts_with("import ") {
+            if !t.ends_with(';') && !t.contains(" from ") {
+                skipping = true; // multi-line import
+            }
+            let aliases = collect_import_aliases(t);
+            if aliases.is_empty() {
+                out.push('\n');
+            } else {
+                out.push_str(&aliases);
+                out.push('\n');
+            }
+            continue;
+        }
+
+        // ── export { … } or export { … } from '…' ────────────────────────────
+        if t.starts_with("export {") || t.starts_with("export{") {
+            if !t.ends_with(';') {
+                skipping = true;
+            }
+            out.push('\n');
+            continue;
+        }
+
+        // ── export const/let/var/function/async function/class ─────────────────
+        if let Some(stripped) = try_strip_export_prefix(line) {
+            out.push_str(&stripped);
+            out.push('\n');
+            continue;
+        }
+
+        // ── export default expr ────────────────────────────────────────────────
+        // Rare in our codebase; keep the value as a named variable.
+        if let Some(rhs) = t.strip_prefix("export default ") {
+            let indent = &line[..line.len() - line.trim_start().len()];
+            out.push_str(&format!("{indent}const _default = {rhs}"));
+            out.push('\n');
+            continue;
+        }
+
+        out.push_str(line);
+        out.push('\n');
+    }
+
+    out
+}
+
+/// If `line` (with leading whitespace preserved) begins with `export <decl-keyword>`,
+/// return the same line with `export ` (7 chars) removed.
+fn try_strip_export_prefix(line: &str) -> Option<String> {
+    const PREFIXES: &[&str] = &[
+        "export const ",
+        "export let ",
+        "export var ",
+        "export function ",
+        "export async function ",
+        "export class ",
+    ];
+    let t = line.trim();
+    for prefix in PREFIXES {
+        if t.starts_with(prefix) {
+            let indent_len = line.len() - line.trim_start().len();
+            // Remove "export " (7 chars) right after the indent
+            return Some(format!(
+                "{}{}",
+                &line[..indent_len],
+                &line[indent_len + 7..]
+            ));
+        }
+    }
+    None
+}
+
+/// For `import { A, B as C, D as E } from '…'` return `"const C = B;\nconst E = D;"`.
+/// Returns an empty string when there are no aliases.
+fn collect_import_aliases(stmt: &str) -> String {
+    let brace_start = match stmt.find('{') {
+        Some(i) => i + 1,
+        None => return String::new(),
+    };
+    let brace_end = match stmt.find('}') {
+        Some(i) => i,
+        None => return String::new(),
+    };
+    let bindings = &stmt[brace_start..brace_end];
+
+    let mut out = String::new();
+    for binding in bindings.split(',') {
+        let b = binding.trim();
+        if let Some(as_pos) = b.find(" as ") {
+            let orig = b[..as_pos].trim();
+            let alias = b[as_pos + 4..].trim();
+            if !out.is_empty() {
+                out.push('\n');
+            }
+            out.push_str(&format!("const {alias} = {orig};"));
+        }
+    }
+    out
+}
+
+// ═══════════════════════════════════════════════════════════════════════════════
+// JS minification
+// ═══════════════════════════════════════════════════════════════════════════════
+
+/// Minify an ES-module file (contains import/export) — returns original on failure.
 fn js_minify_safe(source: &str) -> String {
+    js_minify_inner(source, true)
+}
+
+/// Minify a classic script / IIFE bundle (no import/export) — returns original on failure.
+fn js_minify_script_safe(source: &str) -> String {
+    js_minify_inner(source, false)
+}
+
+fn js_minify_inner(source: &str, is_module: bool) -> String {
     if source.trim().is_empty() {
         return String::new();
     }
-    js_minify(source).unwrap_or_else(|e| {
+    js_minify(source, is_module).unwrap_or_else(|e| {
         eprintln!("cargo:warning=JS minify failed: {e}");
         source.to_string()
     })
 }
 
-fn js_minify(source: &str) -> Result<String, String> {
+fn js_minify(source: &str, is_module: bool) -> Result<String, String> {
     use oxc_allocator::Allocator;
     use oxc_codegen::{Codegen, CodegenOptions, CommentOptions};
     use oxc_minifier::{CompressOptions, CompressOptionsUnused, Minifier, MinifierOptions};
@@ -301,7 +545,11 @@ fn js_minify(source: &str) -> Result<String, String> {
     use oxc_span::SourceType;
 
     let allocator = Allocator::default();
-    let source_type = SourceType::cjs(); // Non-module, script mode
+    let source_type = if is_module {
+        SourceType::mjs()
+    } else {
+        SourceType::cjs()
+    };
     let ret = Parser::new(&allocator, source, source_type).parse();
 
     if !ret.errors.is_empty() {
@@ -311,8 +559,6 @@ fn js_minify(source: &str) -> Result<String, String> {
 
     let mut program = ret.program;
 
-    // Compress (constant-fold, dead-code) — NO mangle (globals would break)
-    // Keep unused top-level functions: they're called cross-file via window.*
     Minifier::new(MinifierOptions {
         mangle: None,
         compress: Some(CompressOptions {
@@ -337,7 +583,7 @@ fn js_minify(source: &str) -> Result<String, String> {
     Ok(output.code)
 }
 
-/// Walk a directory and minify every `.js` in-place (skips generated bundles).
+/// Walk a directory and minify every `.js` in-place (skips generated `app.*` bundles).
 fn minify_tree_js(dir: &Path) {
     let Ok(entries) = fs::read_dir(dir) else {
         return;
@@ -412,11 +658,15 @@ fn json_minify(source: &str) -> String {
 // HTML rewriting
 // ═══════════════════════════════════════════════════════════════════════════════
 
-/// Rewrite index.html: single CSS bundle, inline theme-init, single JS bundle.
+/// Rewrite index.html for release:
+///   - Collapse all `<link stylesheet href="/css/…">` into the single CSS bundle.
+///   - Inline `theme-init.js` as a `<script>` block.
+///   - Replace all `<script type="module" src="…">` with the single JS bundle.
+///   - Leave the non-module `sw-register.js` script untouched.
 fn rewrite_index_html(html: &str, css_path: &str, js_path: &str, inline_theme_js: &str) -> String {
     let mut out: Vec<String> = Vec::with_capacity(html.lines().count());
     let mut css_done = false;
-    let mut defer_done = false;
+    let mut js_done = false;
 
     for line in html.lines() {
         let t = line.trim();
@@ -436,22 +686,19 @@ fn rewrite_index_html(html: &str, css_path: &str, js_path: &str, inline_theme_js
             continue;
         }
 
-        // ── Replace all defer <script>s with single bundle ──────────────────
-        if t.starts_with("<script") && t.contains("defer") && t.contains("src=\"") {
-            if !defer_done {
-                out.push(format!("    <script defer src=\"{js_path}\"></script>"));
-                defer_done = true;
+        // ── Replace all type="module" scripts with single bundle ─────────────
+        if t.starts_with("<script") && t.contains("type=\"module\"") && t.contains("src=\"") {
+            if !js_done {
+                out.push(format!(
+                    "    <script defer type=\"module\" src=\"{js_path}\"></script>"
+                ));
+                js_done = true;
             }
             continue;
         }
 
-        // ── Drop "Service Worker Registration" comment ──────────────────────
-        if t.contains("Service Worker Registration") {
-            continue;
-        }
-
-        // ── Drop "Styles" / "Scripts" section comments ──────────────────────
-        if t.starts_with("<!--") && (t.contains("Styles") || t.contains("Scripts (defer")) {
+        // ── Drop "Styles" / "Scripts" section comments ───────────────────────
+        if t.starts_with("<!--") && (t.contains("Styles") || t.contains("Scripts")) {
             continue;
         }
 
@@ -481,8 +728,6 @@ fn update_sw_cache(sw: &str, css_bundle: &str, js_bundle: &str) -> String {
 
     format!(
         "{before}const ASSETS_TO_CACHE = [\n\
-         \x20 '/',\n\
-         \x20 '/index.html',\n\
          \x20 '/css/{css_bundle}',\n\
          \x20 '/js/{js_bundle}',\n\
          \x20 '/locales/en.json',\n\
diff --git a/src/infrastructure/services/audio_metadata_service.rs b/src/infrastructure/services/audio_metadata_service.rs
index b162c457..303b2e6a 100644
--- a/src/infrastructure/services/audio_metadata_service.rs
+++ b/src/infrastructure/services/audio_metadata_service.rs
@@ -60,9 +60,7 @@ impl AudioMetadataService {
     ///
     /// All I/O is synchronous (id3 + mp3_duration crates), so this MUST
     /// only be called inside `spawn_blocking`.
-    fn extract_metadata_blocking(
-        file_path: &Path,
-    ) -> Option<AudioMetadataFields> {
+    fn extract_metadata_blocking(file_path: &Path) -> Option<AudioMetadataFields> {
         if !file_path.exists() {
             warn!("File does not exist: {:?}", file_path);
             return None;
@@ -114,13 +112,14 @@ impl AudioMetadataService {
 
         // ── Sync I/O on the blocking thread pool (never stalls Tokio workers) ──
         let path = file_path.to_path_buf();
-        let metadata = tokio::task::spawn_blocking(move || {
-            Self::extract_metadata_blocking(&path)
-        })
-        .await
-        .map_err(|e| {
-            DomainError::internal_error("AudioMetadataService", format!("spawn_blocking join error: {e}"))
-        })?;
+        let metadata = tokio::task::spawn_blocking(move || Self::extract_metadata_blocking(&path))
+            .await
+            .map_err(|e| {
+                DomainError::internal_error(
+                    "AudioMetadataService",
+                    format!("spawn_blocking join error: {e}"),
+                )
+            })?;
 
         let Some(m) = metadata else {
             return Ok(());
diff --git a/src/infrastructure/services/dedup_service.rs b/src/infrastructure/services/dedup_service.rs
index a60ce7f8..34dc96e5 100644
--- a/src/infrastructure/services/dedup_service.rs
+++ b/src/infrastructure/services/dedup_service.rs
@@ -717,7 +717,11 @@ impl DedupService {
             // Also clean up any thumbnail files for these blob hashes
             // (thumbnails are keyed by blob_hash and live under
             // storage_root/.thumbnails/{icon,preview,large}/{hash}.jpg).
-            let thumbnails_root = self.blob_root.parent().unwrap_or(&self.blob_root).join(".thumbnails");
+            let thumbnails_root = self
+                .blob_root
+                .parent()
+                .unwrap_or(&self.blob_root)
+                .join(".thumbnails");
             for (hash, size) in &batch {
                 let blob_path = self.blob_path(hash);
                 if let Err(e) = fs::remove_file(&blob_path).await {
diff --git a/src/infrastructure/services/thumbnail_service_test.rs b/src/infrastructure/services/thumbnail_service_test.rs
index 807fdd41..adaf31db 100644
--- a/src/infrastructure/services/thumbnail_service_test.rs
+++ b/src/infrastructure/services/thumbnail_service_test.rs
@@ -40,7 +40,12 @@ async fn generate_thumbnail_from_blob_path() {
 
     // The key assertion: the service can read from a blob path (not a logical path)
     let result = svc
-        .get_thumbnail("test-file-id", "ab1234567890", ThumbnailSize::Icon, &blob_path)
+        .get_thumbnail(
+            "test-file-id",
+            "ab1234567890",
+            ThumbnailSize::Icon,
+            &blob_path,
+        )
         .await;
 
     let thumb_bytes = result.expect("thumbnail generation should succeed from blob path");
@@ -67,7 +72,12 @@ async fn generate_thumbnail_nonexistent_path_returns_error() {
 
     let bad_path = tmp.path().join("does-not-exist.png");
     let result = svc
-        .get_thumbnail("missing-id", "nonexistent-hash", ThumbnailSize::Icon, &bad_path)
+        .get_thumbnail(
+            "missing-id",
+            "nonexistent-hash",
+            ThumbnailSize::Icon,
+            &bad_path,
+        )
         .await;
 
     assert!(result.is_err(), "should fail for nonexistent file");
diff --git a/src/interfaces/api/handlers/file_handler.rs b/src/interfaces/api/handlers/file_handler.rs
index 6686a464..599b3d1d 100644
--- a/src/interfaces/api/handlers/file_handler.rs
+++ b/src/interfaces/api/handlers/file_handler.rs
@@ -746,7 +746,11 @@ impl FileHandler {
 
             tokio::spawn(async move {
                 tracing::info!("🖼️ Generating thumbnails for: {}", file_id);
-                thumbnail_service.generate_all_sizes_background(file_id, blob_hash_owned, file_path);
+                thumbnail_service.generate_all_sizes_background(
+                    file_id,
+                    blob_hash_owned,
+                    file_path,
+                );
             });
         }
 
diff --git a/src/interfaces/api/handlers/share_handler.rs b/src/interfaces/api/handlers/share_handler.rs
index 0b732583..e76a9af7 100644
--- a/src/interfaces/api/handlers/share_handler.rs
+++ b/src/interfaces/api/handlers/share_handler.rs
@@ -16,7 +16,10 @@ use crate::application::services::share_service::ShareService;
 use crate::{
     application::{
         dtos::share_dto::{CreateShareDto, UpdateShareDto},
-        ports::{file_ports::{FileRetrievalUseCase, OptimizedFileContent}, share_ports::ShareUseCase},
+        ports::{
+            file_ports::{FileRetrievalUseCase, OptimizedFileContent},
+            share_ports::ShareUseCase,
+        },
     },
     common::{di::AppState, errors::ErrorKind},
     domain::entities::share::ShareItemType,
@@ -290,7 +293,7 @@ pub async fn download_shared_file(
                 "Sharing is disabled",
                 "Disabled",
             )
-            .into_response()
+            .into_response();
         }
     };
 
diff --git a/src/interfaces/middleware/auth.rs b/src/interfaces/middleware/auth.rs
index 149eb8e7..1b592289 100644
--- a/src/interfaces/middleware/auth.rs
+++ b/src/interfaces/middleware/auth.rs
@@ -243,10 +243,7 @@ pub async fn auth_middleware(
                             if request.uri().path().starts_with("/webdav") {
                                 return Ok(Response::builder()
                                     .status(StatusCode::UNAUTHORIZED)
-                                    .header(
-                                        header::WWW_AUTHENTICATE,
-                                        r#"Basic realm="OxiCloud""#,
-                                    )
+                                    .header(header::WWW_AUTHENTICATE, r#"Basic realm="OxiCloud""#)
                                     .header(header::CONTENT_TYPE, "text/plain; charset=utf-8")
                                     .body(axum::body::Body::from(
                                         "Invalid username or app password",
diff --git a/static/admin.html b/static/admin.html
index 2522c776..aa21b343 100644
--- a/static/admin.html
+++ b/static/admin.html
@@ -5,10 +5,6 @@
         <meta name="viewport" content="width=device-width, initial-scale=1.0" />
         <title>OxiCloud — Admin Panel</title>
         <script src="/js/core/theme-init.js"></script>
-        <script src="/js/core/i18n.js" defer></script>
-        <script src="/js/core/icons.js" defer></script>
-        <script src="/js/core/formatters.js" defer></script>
-        <script src="/js/core/csrf.js" defer></script>
         <link rel="stylesheet" href="/css/main.css" />
         <link rel="stylesheet" href="/css/views/admin.css" />
     </head>
@@ -608,6 +604,6 @@
             </div>
         </div>
 
-        <script src="/js/views/admin/admin.js" defer></script>
+        <script type="module" src="/js/views/admin/admin.js"></script>
     </body>
 </html>
diff --git a/static/device-verify.html b/static/device-verify.html
index 3e227450..5fe3e6a3 100644
--- a/static/device-verify.html
+++ b/static/device-verify.html
@@ -48,7 +48,6 @@
     <div id="status-error" class="status error hidden"></div>
   </div>
 
-  <script src="/js/core/csrf.js"></script>
-  <script src="/js/views/device-verify/device-verify.js"></script>
+  <script type="module" src="/js/views/device-verify/device-verify.js"></script>
 </body>
 </html>
diff --git a/static/index.html b/static/index.html
index 96227e2a..b6b034cc 100644
--- a/static/index.html
+++ b/static/index.html
@@ -19,38 +19,37 @@
     <link rel="stylesheet" href="/css/views/music.css">
 
     <!-- Scripts (defer: download in parallel, execute in order, after HTML parsed) -->
-    <script defer src="/js/core/i18n.js"></script>
-    <script defer src="/js/core/csrf.js"></script>
-    <script defer src="/js/core/languageSelector.js"></script>
-    <script defer src="/js/core/notifications.js"></script>
-    <script defer src="/js/core/modal.js"></script>
-    <script defer src="/js/core/formatters.js"></script>
-    <script defer src="/js/app/state.js"></script>
-    <script defer src="/js/app/uiFileTypes.js"></script>
-    <script defer src="/js/app/uiNotifications.js"></script>
-    <script defer src="/js/app/ui.js"></script>
-    <script defer src="/js/features/files/contextMenus.js"></script>
-    <script defer src="/js/features/files/fileOperations.js"></script>
-    <script defer src="/js/features/files/multiSelect.js"></script>
-    <script defer src="/js/features/files/search.js"></script>
-    <script defer src="/js/features/library/favorites.js"></script>
-    <script defer src="/js/features/library/recent.js"></script>
-    <script defer src="/js/features/library/photos.js"></script>
-    <script defer src="/js/features/library/photosLightbox.js"></script>
-    <script defer src="/js/features/library/music.js"></script>
-    <script defer src="/js/features/sharing/fileSharing.js"></script>
-    <script defer src="/js/views/shared/sharedView.js"></script>
-    <script defer src="/js/features/files/inlineViewer.js"></script>
-    <script defer src="/js/features/files/wopiEditor.js"></script>
-    <script defer src="/js/core/icons.js"></script>
-    <script defer src="/js/app/navigation.js"></script>
-    <script defer src="/js/app/authSession.js"></script>
-    <script defer src="/js/app/userMenu.js"></script>
-    <script defer src="/js/app/filesView.js"></script>
-    <script defer src="/js/app/trashView.js"></script>
-    <script defer src="/js/app/searchView.js"></script>
-    <script defer src="/js/app/main.js"></script>
-    <script defer src="/js/app/bootstrap.js"></script>
+    <script defer type="module" src="/js/core/i18n.js"></script>
+    <script defer type="module" src="/js/core/csrf.js"></script>
+    <script defer type="module" src="/js/core/languageSelector.js"></script>
+    <script defer type="module" src="/js/core/notifications.js"></script>
+    <script defer type="module" src="/js/core/modal.js"></script>
+    <script defer type="module" src="/js/core/formatters.js"></script>
+    <script defer type="module" src="/js/app/state.js"></script>
+    <script defer type="module" src="/js/app/uiFileTypes.js"></script>
+    <script defer type="module" src="/js/app/uiNotifications.js"></script>
+    <script defer type="module" src="/js/app/ui.js"></script>
+    <script defer type="module" src="/js/features/files/contextMenus.js"></script>
+    <script defer type="module" src="/js/features/files/fileOperations.js"></script>
+    <script defer type="module" src="/js/features/files/multiSelect.js"></script>
+    <script defer type="module" src="/js/features/files/search.js"></script>
+    <script defer type="module" src="/js/features/library/favorites.js"></script>
+    <script defer type="module" src="/js/features/library/recent.js"></script>
+    <script defer type="module" src="/js/features/library/photos.js"></script>
+    <script defer type="module" src="/js/features/library/music.js"></script>
+    <script defer type="module" src="/js/features/sharing/fileSharing.js"></script>
+    <script defer type="module" src="/js/views/shared/sharedView.js"></script>
+    <script defer type="module" src="/js/features/files/inlineViewer.js"></script>
+    <script defer type="module" src="/js/features/files/wopiEditor.js"></script>
+    <script defer type="module" src="/js/core/icons.js"></script>
+    <script defer type="module" src="/js/app/navigation.js"></script>
+    <script defer type="module" src="/js/app/authSession.js"></script>
+    <script defer type="module" src="/js/app/userMenu.js"></script>
+    <script defer type="module" src="/js/app/filesView.js"></script>
+    <script defer type="module" src="/js/app/trashView.js"></script>
+    <script defer type="module" src="/js/app/searchView.js"></script>
+    <script defer type="module" src="/js/app/main.js"></script>
+    <script defer type="module" src="/js/app/bootstrap.js"></script>
 
     <!-- Service Worker Registration -->
     <script defer src="/js/core/sw-register.js"></script>
diff --git a/static/js/app/authSession.js b/static/js/app/authSession.js
index f756c8b9..a1ef161e 100644
--- a/static/js/app/authSession.js
+++ b/static/js/app/authSession.js
@@ -2,6 +2,12 @@
  * Authentication/session bootstrap and home-folder resolution
  */
 
+import { getCsrfHeaders } from '../core/csrf.js';
+import { loadFiles } from './filesView.js';
+import { updateStorageUsageDisplay } from './main.js';
+import { app } from './state.js';
+import { ui } from './ui.js';
+
 async function refreshUserData() {
     const USER_DATA_KEY = 'oxicloud_user';
 
@@ -24,7 +30,7 @@ async function refreshUserData() {
         console.log('Storage from server: used=', userData.storage_used_bytes, 'quota=', userData.storage_quota_bytes);
 
         localStorage.setItem(USER_DATA_KEY, JSON.stringify(userData));
-        window.updateStorageUsageDisplay(userData);
+        updateStorageUsageDisplay(userData);
         return userData;
     } catch (error) {
         console.error('Error refreshing user data:', error);
@@ -89,7 +95,7 @@ async function checkAuthentication() {
             if (menuName) menuName.textContent = userData.username;
             if (menuEmail) menuEmail.textContent = userData.email || '';
 
-            window.updateStorageUsageDisplay(userData);
+            updateStorageUsageDisplay(userData);
 
             // Validate session BEFORE loading files to avoid 401 race condition
             const freshData = await refreshUserData();
@@ -133,8 +139,8 @@ async function checkAuthentication() {
                     document.querySelectorAll('.user-avatar, .user-menu-avatar').forEach((el) => {
                         el.textContent = userInitials;
                     });
-                    window.updateStorageUsageDisplay(freshData);
-                    resolveHomeFolder().then(() => window.loadFiles());
+                    updateStorageUsageDisplay(freshData);
+                    resolveHomeFolder().then(() => loadFiles());
                 } else {
                     console.warn('Could not retrieve user data, redirecting to login');
                     localStorage.removeItem(USER_DATA_KEY);
@@ -154,8 +160,6 @@ async function checkAuthentication() {
 }
 
 async function resolveHomeFolder() {
-    const app = window.app;
-
     if (app.userHomeFolderId) return;
     try {
         const response = await fetch('/api/folders', {
@@ -173,22 +177,20 @@ async function resolveHomeFolder() {
             app.userHomeFolderName = home.name;
             app.currentPath = home.id;
             app.breadcrumbPath = [];
-            window.ui.updateBreadcrumb();
+            ui.updateBreadcrumb();
             console.log(`Home folder resolved: ${home.name} (${home.id})`);
         } else {
             console.warn('No root folders found for user');
             app.currentPath = '';
             app.breadcrumbPath = [];
-            window.ui.updateBreadcrumb();
+            ui.updateBreadcrumb();
         }
     } catch (error) {
         console.error('Error resolving home folder:', error);
         app.currentPath = '';
         app.breadcrumbPath = [];
-        window.ui.updateBreadcrumb();
+        ui.updateBreadcrumb();
     }
 }
 
-window.refreshUserData = refreshUserData;
-window.checkAuthentication = checkAuthentication;
-window.resolveHomeFolder = resolveHomeFolder;
+export { checkAuthentication, refreshUserData, resolveHomeFolder };
diff --git a/static/js/app/bootstrap.js b/static/js/app/bootstrap.js
index 54d45a16..fcdd327f 100644
--- a/static/js/app/bootstrap.js
+++ b/static/js/app/bootstrap.js
@@ -2,13 +2,10 @@
  * OxiCloud - App bootstrap
  * Isolated startup trigger for the main application initializer.
  */
+import { initApp } from './main.js';
 
 if (document.readyState === 'loading') {
-    document.addEventListener('DOMContentLoaded', () => {
-        if (typeof window.initApp === 'function') {
-            window.initApp();
-        }
-    });
-} else if (typeof window.initApp === 'function') {
-    window.initApp();
+    document.addEventListener('DOMContentLoaded', initApp);
+} else {
+    initApp();
 }
diff --git a/static/js/app/filesView.js b/static/js/app/filesView.js
index 4faa2221..81fff22e 100644
--- a/static/js/app/filesView.js
+++ b/static/js/app/filesView.js
@@ -1,5 +1,16 @@
 // @ts-check
 
+import { i18n } from '../core/i18n.js';
+import { inlineViewer } from '../features/files/inlineViewer.js';
+import { multiSelect } from '../features/files/multiSelect.js';
+import { resolveHomeFolder } from './authSession.js';
+import { updateHistory } from './main.js';
+import { app } from './state.js';
+import { ui } from './ui.js';
+import { uiNotifications } from './uiNotifications.js';
+
+let isLoadingFiles = false;
+
 // TODO move to features/files/fileOperations.js ?
 /**
  * @typedef {Object} FolderInfo
@@ -48,8 +59,6 @@ async function getFolder(id) {
  * rebuild breadcrumb from selected folder (iterate up to root)
  */
 async function rebuildBreadCrumb() {
-    const app = window.app;
-
     /**
      * Store the leaf (this is the current displayed folder)
      * @type {FolderInfo | null}
@@ -87,10 +96,7 @@ async function rebuildBreadCrumb() {
         } catch (_e) {
             console.log(`Error loading information from folder ${app.currentPath}, falling back to ${app.userHomeFolderId}`);
             // fallback of root
-            window.uiNotifications.show(
-                'error: folder not found or permission denied',
-                'the given folder is not available or you do not have sufficient rights'
-            );
+            uiNotifications.show('error: folder not found or permission denied', 'the given folder is not available or you do not have sufficient rights');
             app.breadcrumbPath = [];
             id = app.userHomeFolderId;
             app.currentPath = id;
@@ -109,33 +115,31 @@ async function rebuildBreadCrumb() {
  * @param {boolean} [options.forceRefresh] force refresh of content
  */
 async function loadFiles(options = { insertHistory: true }) {
-    const app = window.app;
-
     try {
         console.log('Starting loadFiles() - loading files...', options);
 
         const forceRefresh = options.forceRefresh || false;
 
-        if (window.isLoadingFiles) {
+        if (isLoadingFiles) {
             console.log('A file load is already in progress, ignoring request');
             return;
         }
 
-        window.isLoadingFiles = true;
+        isLoadingFiles = true;
 
         // This to avoid blinking page, a better solution would be to put loading on an overlay and remove timeout
         const loadingFiles = setTimeout(() => {
             // display loader after few delay (will be canceled if result take less time)
-            window.ui.showError(`
+            ui.showError(`
                 <div class="files-loading-spinner">
                     <div class="spinner"></div>
-                    <span>${window.i18n ? window.i18n.t('files.loading') : 'Loading files…'}</span>
+                    <span>${i18n ? i18n.t('files.loading') : 'Loading files…'}</span>
                 </div>
             `);
         }, 100);
 
         if (!app.userHomeFolderId) {
-            await window.resolveHomeFolder();
+            await resolveHomeFolder();
         }
 
         const timestamp = Math.floor(Date.now() / 1000);
@@ -143,9 +147,9 @@ async function loadFiles(options = { insertHistory: true }) {
         await rebuildBreadCrumb();
 
         // request a breadcrumb paint
-        window.ui.updateBreadcrumb();
+        ui.updateBreadcrumb();
 
-        window.updateHistory(options.insertHistory || false);
+        updateHistory(options.insertHistory || false);
 
         let url;
 
@@ -154,7 +158,7 @@ async function loadFiles(options = { insertHistory: true }) {
                 url = `/api/folders/${app.userHomeFolderId}/listing?t=${timestamp}`;
                 app.currentPath = app.userHomeFolderId;
                 app.breadcrumbPath = [];
-                window.ui.updateBreadcrumb();
+                ui.updateBreadcrumb();
                 console.log(`Loading user folder: ${app.userHomeFolderName} (${app.userHomeFolderId})`);
             } else {
                 url = `/api/folders?t=${timestamp}`;
@@ -193,7 +197,7 @@ async function loadFiles(options = { insertHistory: true }) {
         if (response.status === 401 || response.status === 403) {
             console.warn('Auth error when loading files, showing empty list');
             // FIXME: i18n
-            window.ui.showError(`<p>Could not load files</p>`);
+            ui.showError(`<p>Could not load files</p>`);
             return;
         }
 
@@ -203,44 +207,44 @@ async function loadFiles(options = { insertHistory: true }) {
 
         const listing = await response.json();
 
-        window.ui._items.clear();
-        window.ui.resetFilesList();
-        if (window.multiSelect) {
-            window.multiSelect.clear();
-            window.multiSelect.init(); // this will wire buttons & select-all-checkbox
+        ui._items.clear();
+        ui.resetFilesList();
+        if (multiSelect) {
+            multiSelect.clear();
+            multiSelect.init(); // this will wire buttons & select-all-checkbox
         }
 
         const folderList = Array.isArray(listing.folders) ? listing.folders : [];
         const fileList = Array.isArray(listing.files) ? listing.files : [];
 
         if (folderList.length === 0 && fileList.length === 0) {
-            window.ui.showEmptyList();
+            ui.showEmptyList();
         } else {
-            window.ui.renderFolders(folderList);
-            window.ui.renderFiles(fileList);
+            ui.renderFolders(folderList);
+            ui.renderFiles(fileList);
 
             // check if a file was provided
-            if (window.app.viewFile) {
+            if (app.viewFile) {
                 let fileFound = null;
 
                 // lookup for the given fle
                 for (const file of fileList) {
-                    if (file.id === window.app.viewFile) {
+                    if (file.id === app.viewFile) {
                         fileFound = file;
                         break;
                     }
                 }
 
                 if (fileFound) {
-                    console.log(`file ${window.app.viewFile} found, calling viewer`);
-                    await window.inlineViewer.openFile(fileFound);
+                    console.log(`file ${app.viewFile} found, calling viewer`);
+                    await inlineViewer.openFile(fileFound);
                 } else {
                     // remove file
-                    console.log(`file ${window.app.viewFile} not found`);
-                    window.app.viewFile = null;
+                    console.log(`file ${app.viewFile} not found`);
+                    app.viewFile = null;
 
                     // correct url/history as file is not found
-                    window.updateHistory(false);
+                    updateHistory(false);
                 }
             }
         }
@@ -248,10 +252,10 @@ async function loadFiles(options = { insertHistory: true }) {
         console.log(`Loaded ${folderList.length} folders and ${fileList.length} files`);
     } catch (error) {
         console.error('Error loading folders:', error);
-        window.ui.showNotification('Error', 'Could not load files and folders');
+        ui.showNotification('Error', 'Could not load files and folders');
     } finally {
-        window.isLoadingFiles = false;
+        isLoadingFiles = false;
     }
 }
 
-window.loadFiles = loadFiles;
+export { loadFiles };
diff --git a/static/js/app/main.js b/static/js/app/main.js
index d7ac93cb..fdba54f0 100644
--- a/static/js/app/main.js
+++ b/static/js/app/main.js
@@ -3,8 +3,31 @@
  * This file contains the core functionality, initialization and state management
  */
 
-const app = window.app;
-const elements = window.appElements;
+import { formatFileSize, formatQuotaSize } from '../core/formatters.js';
+import { i18n } from '../core/i18n.js';
+import { Modal } from '../core/modal.js';
+import { fileOps } from '../features/files/fileOperations.js';
+import { multiSelect } from '../features/files/multiSelect.js';
+import { favorites } from '../features/library/favorites.js';
+import { recent } from '../features/library/recent.js';
+import { fileSharing } from '../features/sharing/fileSharing.js';
+import { sharedView } from '../views/shared/sharedView.js';
+import { checkAuthentication } from './authSession.js';
+import { loadFiles } from './filesView.js';
+import {
+    switchToFavoritesSection,
+    switchToFilesSection,
+    switchToMusicSection,
+    switchToPhotosSection,
+    switchToRecentFilesSection,
+    switchToSharedSection,
+    switchToTrashSection
+} from './navigation.js';
+import { performSearch } from './searchView.js';
+import { app, appElements as elements } from './state.js';
+import { loadTrashItems } from './trashView.js';
+import { ui } from './ui.js';
+import { setupUserMenu } from './userMenu.js';
 
 // Upload dropdown listener state (prevents accumulated listeners)
 /** @type { function | null } */
@@ -125,8 +148,8 @@ function setActionsBarMode(mode, force = false) {
     elements.gridViewBtn = document.getElementById('grid-view-btn');
     elements.listViewBtn = document.getElementById('list-view-btn');
 
-    if (window.i18n?.translateElement) {
-        window.i18n.translateElement(elements.actionsBar);
+    if (i18n?.translateElement) {
+        i18n.translateElement(elements.actionsBar);
     }
 
     if (mode === 'files') {
@@ -159,7 +182,7 @@ function setupActionsBarDelegation() {
                 break;
             }
             case 'new-folder-btn': {
-                const folderName = await window.Modal.promptNewFolder();
+                const folderName = await Modal.promptNewFolder();
                 if (folderName) {
                     fileOps.createFolder(folderName);
                 }
@@ -173,14 +196,14 @@ function setupActionsBarDelegation() {
                 break;
             case 'empty-trash-btn':
                 if (await fileOps.emptyTrash()) {
-                    window.loadTrashItems();
+                    loadTrashItems();
                 }
                 break;
             case 'clear-recent-btn':
-                if (window.recent) {
-                    window.recent.clearRecentFiles();
-                    window.recent.displayRecentFiles();
-                    window.ui.showNotification('Cleanup completed', 'Recent files history has been cleared');
+                if (recent) {
+                    recent.clearRecentFiles();
+                    recent.displayRecentFiles();
+                    ui.showNotification('Cleanup completed', 'Recent files history has been cleared');
                 }
                 break;
             default:
@@ -245,8 +268,6 @@ function deserializeHash() {
  * @param {boolean} insertHistory true to change url and browser's history, false to change url only
  */
 function updateHistory(insertHistory) {
-    const app = window.app;
-
     const historyData = {
         section: app.currentSection,
         id: app.currentFolder,
@@ -259,8 +280,8 @@ function updateHistory(insertHistory) {
         historyData.id = app.currentFolder;
         historyUrl = historyUrl.concat('/folder/', app.currentFolderInfo.id);
 
-        if (window.app.viewFile) {
-            historyUrl = historyUrl.concat('/file/', window.app.viewFile);
+        if (app.viewFile) {
+            historyUrl = historyUrl.concat('/file/', app.viewFile);
         }
         // update title
         document.title = `OxiCloud: ${app.currentFolderInfo.path}`;
@@ -281,7 +302,7 @@ function updateHistory(insertHistory) {
  * @returns
  */
 function switchSectionTo(section) {
-    if (window.app.currentSection === section)
+    if (app.currentSection === section)
         // no change ...
         return;
 
@@ -324,8 +345,8 @@ function initApp() {
     cacheElements();
 
     // Initialize file sharing module first
-    if (window.fileSharing?.init) {
-        window.fileSharing.init();
+    if (fileSharing?.init) {
+        fileSharing.init();
     } else {
         console.warn('fileSharing module not fully initialized');
     }
@@ -338,35 +359,26 @@ function initApp() {
     // Setup event listeners
     setupEventListeners();
 
-    // Ensure inline viewer is initialized
-    if (!window.inlineViewer && typeof InlineViewer !== 'undefined') {
-        try {
-            window.inlineViewer = new InlineViewer();
-        } catch (e) {
-            console.error('Error initializing inline viewer:', e);
-        }
-    }
-
     // Initialize favorites module if available
-    if (window.favorites?.init) {
+    if (favorites?.init) {
         console.log('Initializing favorites module');
-        window.favorites.init();
+        favorites.init();
     } else {
         console.warn('Favorites module not available or not initializable');
     }
 
     // Initialize recent files module if available
-    if (window.recent?.init) {
+    if (recent?.init) {
         console.log('Initializing recent files module');
-        window.recent.init();
+        recent.init();
     } else {
         console.warn('Recent files module not available or not initializable');
     }
 
     // Initialize multi-select / batch actions
-    if (window.multiSelect?.init) {
+    if (multiSelect?.init) {
         console.log('Initializing multi-select module');
-        window.multiSelect.init();
+        multiSelect.init();
     }
 
     window.addEventListener('authenticationDone', () => {
@@ -376,33 +388,33 @@ function initApp() {
         if (hashContext.section === 'files') {
             if (hashContext.path) {
                 console.log(`init: reusing folder from hash URL: ${hashContext.path}`);
-                window.app.currentPath = hashContext.path;
+                app.currentPath = hashContext.path;
             }
 
             if (hashContext.file !== null) {
-                window.app.viewFile = hashContext.file;
+                app.viewFile = hashContext.file;
             }
-            window.loadFiles();
+            loadFiles();
         }
     });
 
     // Wait for translations to load before checking authentication
-    if (window.i18n?.isLoaded?.()) {
+    if (i18n?.isLoaded?.()) {
         // Translations already loaded, proceed with authentication
-        window.checkAuthentication();
+        checkAuthentication();
     } else {
         // Wait for translations to be loaded before proceeding
         console.log('Waiting for translations to load...');
         window.addEventListener('translationsLoaded', () => {
             console.log('Translations loaded, proceeding with authentication');
-            window.checkAuthentication();
+            checkAuthentication();
         });
 
         // Set a timeout as a fallback in case translations take too long
         setTimeout(() => {
-            if (!window.i18n?.isLoaded?.()) {
+            if (!i18n?.isLoaded?.()) {
                 console.warn('Translations loading timeout, proceeding with authentication anyway');
-                window.checkAuthentication();
+                checkAuthentication();
             }
         }, 3000); // 3 second timeout
     }
@@ -493,14 +505,14 @@ function setupEventListeners() {
             const hashContext = deserializeHash();
             switchSectionTo(hashContext.section);
             if (hashContext.path) {
-                window.app.currentPath = hashContext.path;
-                window.loadFiles({ insertHistory: false });
+                app.currentPath = hashContext.path;
+                loadFiles({ insertHistory: false });
             }
         } else {
             // change is from history, data provided in event
             switchSectionTo(e.state.section);
-            window.app.currentPath = e.state.id;
-            window.loadFiles({ insertHistory: false });
+            app.currentPath = e.state.id;
+            loadFiles({ insertHistory: false });
         }
     });
 
@@ -512,19 +524,19 @@ function setupEventListeners() {
             const query = elements.searchInput.value.trim();
 
             // In shared view, filter locally
-            if (app.isSharedView && window.sharedView) {
-                window.sharedView.filterAndSortItems();
+            if (app.isSharedView && sharedView) {
+                sharedView.filterAndSortItems();
                 return;
             }
 
             if (query) {
-                window.performSearch(query);
+                performSearch(query);
             } else if (app.isSearchMode) {
                 // If search is empty and we're in search mode, return to normal view
                 app.isSearchMode = false;
                 app.currentPath = '';
                 ui.updateBreadcrumb('');
-                window.loadFiles();
+                loadFiles();
             }
         }
     });
@@ -536,7 +548,7 @@ function setupEventListeners() {
 
         if (query.length >= SEARCH_MIN_CHARS) {
             searchDebounceTimer = setTimeout(() => {
-                window.performSearch(query);
+                performSearch(query);
             }, SEARCH_DEBOUNCE_MS);
         } else if (query.length === 0 && app.isSearchMode) {
             // User cleared the search input — return to normal view
@@ -544,7 +556,7 @@ function setupEventListeners() {
                 app.isSearchMode = false;
                 app.currentPath = '';
                 ui.updateBreadcrumb('');
-                window.loadFiles();
+                loadFiles();
             }, SEARCH_DEBOUNCE_MS);
         }
     });
@@ -554,7 +566,7 @@ function setupEventListeners() {
         if (searchDebounceTimer) clearTimeout(searchDebounceTimer);
         const query = elements.searchInput.value.trim();
         if (query) {
-            window.performSearch(query);
+            performSearch(query);
         }
     });
 
@@ -627,12 +639,12 @@ function setupEventListeners() {
 
                 default:
                     // Use the proper switchToFilesView function which handles all UI restoration
-                    window.switchToFilesSection();
+                    switchToFilesSection();
                     // FIXME: because fileview handles it: need to converge code
                     _updateHistory = false;
             }
 
-            document.title = `OxiCloud: ${window.i18n.t(itemI18nKey)}`;
+            document.title = `OxiCloud: ${i18n.t(itemI18nKey)}`;
 
             if (_updateHistory) {
                 updateHistory(true);
@@ -649,7 +661,7 @@ function setupEventListeners() {
     }
 
     // User menu
-    window.setupUserMenu();
+    setupUserMenu();
 
     // Global events to close context menus and deselect cards
     document.addEventListener('click', (e) => {
@@ -666,18 +678,19 @@ function setupEventListeners() {
     });
 }
 
-// Expose needed functions to global scope
-window.setActionsBarMode = setActionsBarMode;
+// View-switching actions moved to app/navigation.js
 
-// Set up global selectFolder function for navigation
-window.selectFolder = (id, name) => {
+/**
+ * Navigate into a folder and refresh the file list.
+ * @param {string} id
+ * @param {string} name
+ */
+export function selectFolder(id, name) {
     app.breadcrumbPath.push({ id, name });
     app.currentPath = id;
     ui.updateBreadcrumb();
-    window.loadFiles();
-};
-
-// View-switching actions moved to app/navigation.js
+    loadFiles();
+}
 
 /**
  * Update the storage usage display with the user's actual storage usage
@@ -719,8 +732,8 @@ function updateStorageUsageDisplay(userData) {
         storageInfo.removeAttribute('data-i18n');
 
         // Use i18n if available
-        if (window.i18n?.t) {
-            storageInfo.textContent = window.i18n.t('storage.used', {
+        if (i18n?.t) {
+            storageInfo.textContent = i18n.t('storage.used', {
                 percentage: usagePercentage,
                 used: usedFormatted,
                 total: quotaFormatted
@@ -733,9 +746,4 @@ function updateStorageUsageDisplay(userData) {
     console.log(`Updated storage display: ${usagePercentage}% (${usedFormatted} / ${quotaFormatted})`);
 }
 
-window.updateStorageUsageDisplay = updateStorageUsageDisplay;
-
-// Initialize app when DOM is ready
-window.initApp = initApp;
-window.updateHistory = updateHistory;
-window.deserializeHash = deserializeHash;
+export { deserializeHash, initApp, setActionsBarMode, updateHistory, updateStorageUsageDisplay };
diff --git a/static/js/app/navigation.js b/static/js/app/navigation.js
index 14269646..6884eff3 100644
--- a/static/js/app/navigation.js
+++ b/static/js/app/navigation.js
@@ -3,6 +3,19 @@
  * Extracted from main.js to keep navigation concerns isolated.
  */
 
+import { i18n } from '../core/i18n.js';
+import { multiSelect } from '../features/files/multiSelect.js';
+import { favorites } from '../features/library/favorites.js';
+import { musicView } from '../features/library/music.js';
+import { photosView } from '../features/library/photos.js';
+import { recent } from '../features/library/recent.js';
+import { sharedView } from '../views/shared/sharedView.js';
+import { loadFiles } from './filesView.js';
+import { setActionsBarMode } from './main.js';
+import { app, appElements } from './state.js';
+import { loadTrashItems } from './trashView.js';
+import { ui } from './ui.js';
+
 /**
  * Sync the hidden class and inline display for the grid/list containers
  * based on the current view preference.
@@ -12,7 +25,7 @@ function syncViewContainers() {
     const gridViewBtn = document.getElementById('grid-view-btn');
     const listViewBtn = document.getElementById('list-view-btn');
 
-    const isGrid = window.app.currentView === 'grid';
+    const isGrid = app.currentView === 'grid';
     if (isGrid) {
         filesList.classList.remove('files-list-view');
         filesList.classList.add('files-grid-view');
@@ -89,13 +102,6 @@ function initSidebarToggle() {
             }
         });
     });
-
-    // Expose functions globally
-    window.sidebarToggle = {
-        open: openSidebar,
-        close: closeSidebar,
-        toggle: toggleSidebar
-    };
 }
 
 // Initialize sidebar toggle when DOM is ready
@@ -128,17 +134,17 @@ function getSectionFromNavItem(navItem) {
  * @returns {boolean} true if the section changed
  */
 function setCurrentSection(section) {
-    if (window.app.currentSection === section) return false;
+    if (app.currentSection === section) return false;
 
     // Set all view flags - true for active section, false for others
     Object.entries(VIEW_FLAGS).forEach(([key, flag]) => {
-        window.app[flag] = key === section;
+        app[flag] = key === section;
     });
 
-    window.app.currentSection = section;
+    app.currentSection = section;
 
     // Update nav item active classes by finding matching item from DOM
-    window.appElements.navItems.forEach((item) => {
+    appElements.navItems.forEach((item) => {
         const itemSection = getSectionFromNavItem(item);
         item.classList.toggle('active', itemSection === section);
     });
@@ -146,22 +152,22 @@ function setCurrentSection(section) {
     // Update page title
     const titleKey = `nav.${section}`;
     const defaultTitle = section.charAt(0).toUpperCase() + section.slice(1);
-    window.appElements.pageTitle.textContent = window.i18n ? window.i18n.t(titleKey) : defaultTitle;
-    window.appElements.pageTitle.setAttribute('data-i18n', titleKey);
+    appElements.pageTitle.textContent = i18n ? i18n.t(titleKey) : defaultTitle;
+    appElements.pageTitle.setAttribute('data-i18n', titleKey);
 
     // Hide sharedView when switching to any other section
-    if (section !== 'shared' && window.sharedView) {
-        window.sharedView.hide();
+    if (section !== 'shared' && sharedView) {
+        sharedView.hide();
     }
 
     // Hide photosView when switching to any other section
-    if (section !== 'photos' && window.photosView) {
-        window.photosView.hide();
+    if (section !== 'photos' && photosView) {
+        photosView.hide();
     }
 
     // Hide musicView when switching to any other section
-    if (section !== 'music' && window.musicView) {
-        window.musicView.hide();
+    if (section !== 'music' && musicView) {
+        musicView.hide();
     }
 
     return true;
@@ -175,27 +181,27 @@ function switchToSharedSection() {
     breadcrumb?.classList.add('hidden');
 
     // Hide actions-bar for shared view
-    window.setActionsBarMode('hidden');
+    setActionsBarMode('hidden');
 
     //reset files view + remove any error
-    window.ui.resetFilesList();
+    ui.resetFilesList();
 
     // Hide file containers
     toggleFileContainer(false);
 
     // Show shared view
-    if (window.sharedView) {
-        window.sharedView.init();
-        window.sharedView.show();
+    if (sharedView) {
+        sharedView.init();
+        sharedView.show();
     }
-    if (window.multiSelect) window.multiSelect.clear();
+    if (multiSelect) multiSelect.clear();
 }
 
 function switchToFilesSection() {
     if (!setCurrentSection('files')) return;
 
     // Set actions bar mode
-    window.setActionsBarMode('files', true);
+    setActionsBarMode('files', true);
 
     // Show breadcrumb (only in Files view)
     const breadcrumb = document.querySelector('.breadcrumb');
@@ -208,22 +214,22 @@ function switchToFilesSection() {
     syncViewContainers();
 
     //reset files view + remove any error
-    window.ui.resetFilesList();
+    ui.resetFilesList();
 
     // Reset to home folder and update breadcrumb
-    window.app.currentPath = window.app.userHomeFolderId || '';
-    window.app.breadcrumbPath = [];
-    window.ui.updateBreadcrumb();
-    if (window.multiSelect) window.multiSelect.clear();
+    app.currentPath = app.userHomeFolderId || '';
+    app.breadcrumbPath = [];
+    ui.updateBreadcrumb();
+    if (multiSelect) multiSelect.clear();
 
-    window.loadFiles();
+    loadFiles();
 }
 
 function switchToFavoritesSection() {
     if (!setCurrentSection('favorites')) return;
 
     // Set actions bar mode
-    window.setActionsBarMode('favorites');
+    setActionsBarMode('favorites');
 
     // Hide breadcrumb (only shown in Files view)
     const breadcrumb = document.querySelector('.breadcrumb');
@@ -236,26 +242,26 @@ function switchToFavoritesSection() {
     syncViewContainers();
 
     //reset files view + remove any error
-    window.ui.resetFilesList();
+    ui.resetFilesList();
 
-    if (window.favorites) {
-        window.favorites.displayFavorites();
+    if (favorites) {
+        favorites.displayFavorites();
     } else {
         console.error('Favorites module not loaded or initialized');
-        window.ui.showError(`
+        ui.showError(`
                 <i class="fas fa-exclamation-circle empty-state-icon error"></i>
                 <p>Error loading the favorites module</p>
             `);
     }
 
-    if (window.multiSelect) window.multiSelect.clear();
+    if (multiSelect) multiSelect.clear();
 }
 
 function switchToRecentFilesSection() {
     if (!setCurrentSection('recent')) return;
 
     // Set actions bar mode
-    window.setActionsBarMode('recent');
+    setActionsBarMode('recent');
 
     // Hide breadcrumb (only shown in Files view)
     const breadcrumb = document.querySelector('.breadcrumb');
@@ -268,18 +274,18 @@ function switchToRecentFilesSection() {
     syncViewContainers();
 
     //reset files view + remove any error
-    window.ui.resetFilesList();
+    ui.resetFilesList();
 
-    if (window.recent) {
-        window.recent.displayRecentFiles();
+    if (recent) {
+        recent.displayRecentFiles();
     } else {
         console.error('Recent files module not loaded or initialized');
-        window.ui.showError(`
+        ui.showError(`
                 <i class="fas fa-exclamation-circle empty-state-icon error"></i>
                 <p>Error loading the recent module</p>
             `);
     }
-    if (window.multiSelect) window.multiSelect.clear();
+    if (multiSelect) multiSelect.clear();
 }
 
 function switchToPhotosSection() {
@@ -290,19 +296,19 @@ function switchToPhotosSection() {
     breadcrumb?.classList.add('hidden');
 
     // Hide actions-bar (photos has its own upload via selection bar)
-    window.setActionsBarMode('hidden');
+    setActionsBarMode('hidden');
 
     //reset files view + remove any error
-    window.ui.resetFilesList();
+    ui.resetFilesList();
 
     // Hide file containers
     toggleFileContainer(false);
 
     // Show photos view
-    if (window.photosView) {
-        window.photosView.show();
+    if (photosView) {
+        photosView.show();
     }
-    if (window.multiSelect) window.multiSelect.clear();
+    if (multiSelect) multiSelect.clear();
 }
 
 function switchToTrashSection() {
@@ -319,15 +325,15 @@ function switchToTrashSection() {
     setActionsBarMode('trash');
 
     //reset files view + remove any error
-    window.ui.resetFilesList();
+    ui.resetFilesList();
 
     //ensure buttons match the current view
     syncViewContainers();
 
     // Load trash items
-    window.loadTrashItems();
+    loadTrashItems();
 
-    if (window.multiSelect) window.multiSelect.clear();
+    if (multiSelect) multiSelect.clear();
 }
 
 function switchToMusicSection() {
@@ -341,27 +347,29 @@ function switchToMusicSection() {
     toggleFileContainer(false);
 
     // Hide actions-bar
-    window.setActionsBarMode('hidden');
+    setActionsBarMode('hidden');
 
     // Reset files view + remove any error
-    window.ui.resetFilesList();
+    ui.resetFilesList();
 
     // Hide list header (created by resetFilesList)
     const listHeader = document.querySelector('.list-header');
     listHeader?.classList.add('hidden');
 
     // Show music view
-    if (window.musicView) {
-        window.musicView.show();
+    if (musicView) {
+        musicView.show();
     }
-    if (window.multiSelect) window.multiSelect.clear();
+    if (multiSelect) multiSelect.clear();
 }
 
-window.switchToFilesSection = switchToFilesSection;
-window.switchToSharedSection = switchToSharedSection;
-window.switchToFavoritesSection = switchToFavoritesSection;
-window.switchToRecentFilesSection = switchToRecentFilesSection;
-window.switchToPhotosSection = switchToPhotosSection;
-window.switchToTrashSection = switchToTrashSection;
-window.switchToMusicSection = switchToMusicSection;
-window.syncViewContainers = syncViewContainers;
+export {
+    switchToFavoritesSection,
+    switchToFilesSection,
+    switchToMusicSection,
+    switchToPhotosSection,
+    switchToRecentFilesSection,
+    switchToSharedSection,
+    switchToTrashSection,
+    syncViewContainers
+};
diff --git a/static/js/app/searchView.js b/static/js/app/searchView.js
index 2dfcfc85..2ace946f 100644
--- a/static/js/app/searchView.js
+++ b/static/js/app/searchView.js
@@ -2,16 +2,23 @@
  * Search view orchestration logic
  */
 
-async function performSearch(query, sortBy) {
-    const app = window.app;
+import { search } from '../features/files/search.js';
+import { resolveHomeFolder } from './authSession.js';
+import { app } from './state.js';
+import { ui } from './ui.js';
 
+/**
+ * @param {string} query
+ * @param {string} [sortBy]
+ */
+async function performSearch(query, sortBy) {
     console.log(`Performing search for: "${query}" (sort: ${sortBy || 'relevance'})`);
 
     try {
         app.isSearchMode = true;
-        window.ui.updateBreadcrumb(`Search: "${query}"`);
+        ui.updateBreadcrumb(`Search: "${query}"`);
 
-        window.ui.showError(`<h3><i class="fas fa-spinner fa-spin search-spinner"></i> Searching for "${query}"...</h3>`);
+        ui.showError(`<h3><i class="fas fa-spinner fa-spin search-spinner"></i> Searching for "${query}"...</h3>`);
 
         const options = {
             recursive: true,
@@ -22,7 +29,7 @@ async function performSearch(query, sortBy) {
         if (!app.isTrashView) {
             // Ensure we have a valid folder_id before searching
             if (!app.currentPath || app.currentPath === '') {
-                await window.resolveHomeFolder();
+                await resolveHomeFolder();
             }
 
             // Only set folder_id if we have a valid value
@@ -32,11 +39,11 @@ async function performSearch(query, sortBy) {
             // If still no valid folder_id, search will be global (without folder_id)
         }
 
-        const searchResults = await window.search.searchFiles(query, options);
-        window.search.displaySearchResults(searchResults);
+        const searchResults = await search.searchFiles(query, options);
+        search.displaySearchResults(searchResults);
     } catch (error) {
         console.error('Search error:', error);
-        window.ui.showNotification('Error', 'Error performing search');
+        ui.showNotification('Error', 'Error performing search');
     }
 }
 
@@ -47,4 +54,4 @@ document.addEventListener('search-resort', (e) => {
     }
 });
 
-window.performSearch = performSearch;
+export { performSearch };
diff --git a/static/js/app/state.js b/static/js/app/state.js
index 1e2bfa7a..9397fcdc 100644
--- a/static/js/app/state.js
+++ b/static/js/app/state.js
@@ -3,7 +3,7 @@
  * Centralized mutable state for app and cached DOM references.
  */
 
-window.app = {
+export const app = {
     currentView: 'grid',
     currentPath: '',
     currentFolder: null,
@@ -29,4 +29,4 @@ window.app = {
     viewFile: null // current file in inline view
 };
 
-window.appElements = {};
+export const appElements = {};
diff --git a/static/js/app/trashView.js b/static/js/app/trashView.js
index 9ad63788..102d8e56 100644
--- a/static/js/app/trashView.js
+++ b/static/js/app/trashView.js
@@ -2,13 +2,20 @@
  * Trash view loading and rendering logic
  */
 
+import { escapeHtml, formatDateTime } from '../core/formatters.js';
+import { i18n } from '../core/i18n.js';
+import { fileOps } from '../features/files/fileOperations.js';
+import { multiSelect } from '../features/files/multiSelect.js';
+import { appElements } from './state.js';
+import { ui } from './ui.js';
+
 async function loadTrashItems() {
-    const elements = window.appElements;
+    const elements = appElements;
 
     try {
-        if (window.multiSelect) window.multiSelect.clear();
-        window.ui.resetFilesList(); // ensure also list visible & error hidden
-        const _tt = window.i18n?.t ? window.i18n.t : (k) => k.split('.').pop();
+        if (multiSelect) multiSelect.clear();
+        ui.resetFilesList(); // ensure also list visible & error hidden
+        const _tt = i18n?.t ? i18n.t : (k) => k.split('.').pop();
         elements.filesList.innerHTML = `
             <div class="list-header trash-header">
                 <div data-i18n="files.name">${_tt('files.name')}</div>
@@ -19,14 +26,14 @@ async function loadTrashItems() {
             </div>
         `;
 
-        window.ui.updateBreadcrumb('');
+        ui.updateBreadcrumb('');
 
-        const trashItems = await window.fileOps.getTrashItems();
+        const trashItems = await fileOps.getTrashItems();
 
         if (trashItems.length === 0) {
-            window.ui.showError(`
+            ui.showError(`
                 <i class="fas fa-trash empty-state-icon"></i>
-                <p>${window.i18n ? window.i18n.t('trash.empty_state') : 'The trash is empty'}</p>
+                <p>${i18n ? i18n.t('trash.empty_state') : 'The trash is empty'}</p>
             `);
             return;
         }
@@ -36,33 +43,27 @@ async function loadTrashItems() {
         });
     } catch (error) {
         console.error('Error loading trash items:', error);
-        window.ui.showNotification('Error', 'Error loading trash items');
+        ui.showNotification('Error', 'Error loading trash items');
     }
 }
 
 function addTrashItemToView(item) {
-    const elements = window.appElements;
+    const elements = appElements;
     const isFile = item.item_type === 'file';
 
-    const formattedDate = window.formatDateTime(item.trashed_at);
+    const formattedDate = formatDateTime(item.trashed_at);
 
     let iconClass;
     let typeLabel;
     let iconSpecialClass = '';
     if (!isFile) {
         iconClass = item.icon_class || 'fas fa-folder';
-        typeLabel = window.i18n ? window.i18n.t('files.file_types.folder') : 'Folder';
+        typeLabel = i18n ? i18n.t('files.file_types.folder') : 'Folder';
     } else {
-        iconClass = item.icon_class || (window.ui?.getIconClass ? window.ui.getIconClass(item.name) : 'fas fa-file');
-        iconSpecialClass = window.ui?.getIconSpecialClass ? window.ui.getIconSpecialClass(item.name) : '';
+        iconClass = item.icon_class || (ui?.getIconClass ? ui.getIconClass(item.name) : 'fas fa-file');
+        iconSpecialClass = ui?.getIconSpecialClass ? ui.getIconSpecialClass(item.name) : '';
         const cat = item.category || '';
-        typeLabel = cat
-            ? window.i18n
-                ? window.i18n.t(`files.file_types.${cat.toLowerCase()}`) || cat
-                : cat
-            : window.i18n
-              ? window.i18n.t('files.file_types.document')
-              : 'Document';
+        typeLabel = cat ? (i18n ? i18n.t(`files.file_types.${cat.toLowerCase()}`) || cat : cat) : i18n ? i18n.t('files.file_types.document') : 'Document';
     }
 
     const isFolder = !isFile;
@@ -85,10 +86,10 @@ function addTrashItemToView(item) {
         <div class="path-cell">${escapeHtml(item.original_path || '--')}</div>
         <div class="date-cell">${escapeHtml(formattedDate)}</div>
         <div class="actions-cell">
-            <button class="btn-restore" title="${window.i18n ? window.i18n.t('trash.restore') : 'Restore'}">
+            <button class="btn-restore" title="${i18n ? i18n.t('trash.restore') : 'Restore'}">
                 <i class="fas fa-undo"></i>
             </button>
-            <button class="btn-delete" title="${window.i18n ? window.i18n.t('trash.delete_permanently') : 'Delete permanently'}">
+            <button class="btn-delete" title="${i18n ? i18n.t('trash.delete_permanently') : 'Delete permanently'}">
                 <i class="fas fa-trash"></i>
             </button>
         </div>
@@ -96,19 +97,19 @@ function addTrashItemToView(item) {
 
     listElement.querySelector('.btn-restore').addEventListener('click', async (e) => {
         e.stopPropagation();
-        if (await window.fileOps.restoreFromTrash(item.id)) {
-            window.loadTrashItems();
+        if (await fileOps.restoreFromTrash(item.id)) {
+            loadTrashItems();
         }
     });
 
     listElement.querySelector('.btn-delete').addEventListener('click', async (e) => {
         e.stopPropagation();
-        if (await window.fileOps.deletePermanently(item.id)) {
-            window.loadTrashItems();
+        if (await fileOps.deletePermanently(item.id)) {
+            loadTrashItems();
         }
     });
 
     elements.filesList.appendChild(listElement);
 }
 
-window.loadTrashItems = loadTrashItems;
+export { loadTrashItems };
diff --git a/static/js/app/ui.js b/static/js/app/ui.js
index 1323207c..1c3e7f83 100644
--- a/static/js/app/ui.js
+++ b/static/js/app/ui.js
@@ -5,6 +5,26 @@
 
 // @ts-check
 
+import { escapeHtml, formatDateTime, formatFileSize } from '../core/formatters.js';
+import { i18n } from '../core/i18n.js';
+import { OxiIcons, replaceIconsInElement } from '../core/icons.js';
+import { contextMenus } from '../features/files/contextMenus.js';
+import { fileOps } from '../features/files/fileOperations.js';
+import { inlineViewer } from '../features/files/inlineViewer.js';
+import { multiSelect } from '../features/files/multiSelect.js';
+import { wopiEditor } from '../features/files/wopiEditor.js';
+import { favorites } from '../features/library/favorites.js';
+import { recent } from '../features/library/recent.js';
+import { fileSharing } from '../features/sharing/fileSharing.js';
+import { loadFiles } from './filesView.js';
+import { updateHistory } from './main.js';
+import { syncViewContainers } from './navigation.js';
+import { app } from './state.js';
+import { uiFileTypes } from './uiFileTypes.js';
+import { uiNotifications } from './uiNotifications.js';
+
+let __rubberBandJustFinished = false;
+
 // UI Module
 const ui = {
     /** @type {HTMLDListElement | null} */
@@ -297,13 +317,13 @@ const ui = {
             document.body.appendChild(playlistDialog);
 
             document.getElementById('playlist-cancel-btn').addEventListener('click', () => {
-                if (window.contextMenus) window.contextMenus.closePlaylistDialog();
+                if (contextMenus) contextMenus.closePlaylistDialog();
             });
         }
 
         // Assign events to menu items
-        if (window.contextMenus) {
-            window.contextMenus.assignMenuEvents();
+        if (contextMenus) {
+            contextMenus.assignMenuEvents();
         } else {
             console.warn('contextMenus module not loaded');
         }
@@ -478,10 +498,10 @@ const ui = {
     switchToGridView() {
         this._hydrateViewIfNeeded();
 
-        window.app.currentView = 'grid';
+        app.currentView = 'grid';
         localStorage.setItem('oxicloud-view', 'grid');
 
-        window.syncViewContainers();
+        syncViewContainers();
     },
 
     /**
@@ -490,10 +510,10 @@ const ui = {
     switchToListView() {
         this._hydrateViewIfNeeded();
 
-        window.app.currentView = 'list';
+        app.currentView = 'list';
         localStorage.setItem('oxicloud-view', 'list');
 
-        window.syncViewContainers();
+        syncViewContainers();
     },
 
     /**
@@ -504,12 +524,12 @@ const ui = {
     updateBreadcrumb() {
         const breadcrumb = document.querySelector('.breadcrumb');
         breadcrumb.innerHTML = '';
-        const path = window.app.breadcrumbPath; // [{id, name}, ...]
+        const path = app.breadcrumbPath; // [{id, name}, ...]
 
         // Helper function to safely get translation text
         const getTranslatedText = (key, defaultValue) => {
-            if (!window.i18n?.t) return defaultValue;
-            return window.i18n.t(key);
+            if (!i18n?.t) return defaultValue;
+            return i18n.t(key);
         };
 
         // -- Home icon (always present, clickable to go to root) --
@@ -519,24 +539,24 @@ const ui = {
         homeIcon.title = getTranslatedText('breadcrumb.home', 'Home');
 
         // Home is always clickable if we have a home folder
-        if (window.app.userHomeFolderId) {
+        if (app.userHomeFolderId) {
             homeIcon.classList.add('breadcrumb-link');
             homeIcon.addEventListener('click', () => {
-                window.app.breadcrumbPath = [];
-                window.app.currentPath = window.app.userHomeFolderId;
+                app.breadcrumbPath = [];
+                app.currentPath = app.userHomeFolderId;
                 this.updateBreadcrumb();
-                window.loadFiles();
+                loadFiles();
             });
         }
         breadcrumb.appendChild(homeIcon);
 
         // -- Root/Home folder name (if available) is always the first element of the breadcrumb --
         // TODO clarify the difference between homeIcon & this first element
-        if (window.app.userHomeFolderName) {
-            if (path.length === 0 || path[0].id !== window.app.userHomeFolderId) {
+        if (app.userHomeFolderName) {
+            if (path.length === 0 || path[0].id !== app.userHomeFolderId) {
                 path.unshift({
-                    name: window.app.userHomeFolderName,
-                    id: window.app.userHomeFolderId
+                    name: app.userHomeFolderName,
+                    id: app.userHomeFolderId
                 });
             }
         }
@@ -561,10 +581,10 @@ const ui = {
                 // Intermediate segment: clickable – truncate path to this level
                 item.classList.add('breadcrumb-link');
                 item.addEventListener('click', () => {
-                    window.app.breadcrumbPath = path.slice(0, index + 1);
-                    window.app.currentPath = segment.id;
+                    app.breadcrumbPath = path.slice(0, index + 1);
+                    app.currentPath = segment.id;
                     this.updateBreadcrumb();
-                    window.loadFiles();
+                    loadFiles();
                 });
 
                 // can drag files on this folder
@@ -611,7 +631,7 @@ const ui = {
      * @returns {boolean}
      */
     isViewableFile(file) {
-        return window.uiFileTypes.isViewableFile(file);
+        return uiFileTypes.isViewableFile(file);
     },
 
     /**
@@ -620,7 +640,7 @@ const ui = {
      * (e.g. trash items).
      */
     getIconClass(fileName) {
-        return window.uiFileTypes.getIconClass(fileName);
+        return uiFileTypes.getIconClass(fileName);
     },
 
     /**
@@ -628,7 +648,7 @@ const ui = {
      * Used as fallback when the backend DTO doesn't include icon_special_class.
      */
     getIconSpecialClass(fileName) {
-        return window.uiFileTypes.getIconSpecialClass(fileName);
+        return uiFileTypes.getIconSpecialClass(fileName);
     },
 
     /**
@@ -637,7 +657,7 @@ const ui = {
      * @param {string} message - Notification message
      */
     showNotification(title, message) {
-        window.uiNotifications.show(title, message);
+        uiNotifications.show(title, message);
     },
 
     /**
@@ -647,7 +667,7 @@ const ui = {
         const menu = document.getElementById('folder-context-menu');
         if (menu) {
             menu.style.display = 'none';
-            window.app.contextMenuTargetFolder = null;
+            app.contextMenuTargetFolder = null;
         }
     },
 
@@ -658,7 +678,7 @@ const ui = {
         const menu = document.getElementById('file-context-menu');
         if (menu) {
             menu.style.display = 'none';
-            window.app.contextMenuTargetFile = null;
+            app.contextMenuTargetFile = null;
         }
     },
 
@@ -679,8 +699,8 @@ const ui = {
     _delegationReady: false,
 
     _getActiveView() {
-        if (window.app && window.app.currentView === 'list') return 'list';
-        if (window.app && window.app.currentView === 'grid') return 'grid';
+        if (app && app.currentView === 'list') return 'list';
+        if (app && app.currentView === 'grid') return 'grid';
 
         const stored = localStorage.getItem('oxicloud-view');
         return stored === 'list' ? 'list' : 'grid';
@@ -737,9 +757,9 @@ const ui = {
      * @param {any} dataTransfer fallback if nothing is selected
      */
     async _dropToFolder(action, targetFolderId, dataTransfer) {
-        const selection = window.multiSelect.getSelection(targetFolderId);
+        const selection = multiSelect.getSelection(targetFolderId);
 
-        window.multiSelect.clear();
+        multiSelect.clear();
 
         if (selection.fileIds.length === 0 && selection.folderIds.length === 0) {
             // try to use dataTransfer (direct move without selection)
@@ -770,20 +790,20 @@ const ui = {
         let result;
         switch (action) {
             case 'copy':
-                result = await window.fileOps.batchCopy(selection.fileIds, selection.folderIds, targetFolderId);
+                result = await fileOps.batchCopy(selection.fileIds, selection.folderIds, targetFolderId);
                 break;
 
             case 'move':
-                result = await window.fileOps.batchMove(selection.fileIds, selection.folderIds, targetFolderId);
+                result = await fileOps.batchMove(selection.fileIds, selection.folderIds, targetFolderId);
                 // redraw directory
-                if (result.success > 0) window.loadFiles();
+                if (result.success > 0) loadFiles();
                 break;
 
             default:
                 console.error(`drag and drop: action ${action} unknown`);
                 return;
         }
-        window.multiSelect.showBatchResult(action, result);
+        multiSelect.showBatchResult(action, result);
         console.log(result);
     },
 
@@ -837,7 +857,7 @@ const ui = {
 
         const openFile = async (file) => {
             if (!file) return;
-            if (window.recent) {
+            if (recent) {
                 document.dispatchEvent(new CustomEvent('file-accessed', { detail: { file } }));
             }
             // WOPI editor intercept: open Office documents in the WOPI editor
@@ -846,8 +866,8 @@ const ui = {
             const imageExts = ['jpg', 'jpeg', 'png', 'gif', 'svg', 'webp', 'bmp', 'ico', 'heic', 'heif', 'avif', 'tiff'];
             const isImage = file.mime_type?.startsWith('image/') || imageExts.includes(ext);
             try {
-                if (!isImage && window.wopiEditor && (await window.wopiEditor.canEdit(file.name))) {
-                    await window.wopiEditor.openInModal(file.id, file.name, 'edit');
+                if (!isImage && wopiEditor && (await wopiEditor.canEdit(file.name))) {
+                    await wopiEditor.openInModal(file.id, file.name, 'edit');
                     return;
                 }
             } catch (e) {
@@ -855,38 +875,38 @@ const ui = {
             }
 
             if (this.isViewableFile(file) || isImage) {
-                if (window.inlineViewer) {
-                    window.inlineViewer.openFile(file);
+                if (inlineViewer) {
+                    inlineViewer.openFile(file);
                     // update history
-                    window.app.viewFile = file.id;
-                    window.updateHistory(false);
+                    app.viewFile = file.id;
+                    updateHistory(false);
                 } else {
-                    window.fileOps.downloadFile(file.id, file.name);
+                    fileOps.downloadFile(file.id, file.name);
                 }
             } else {
-                window.fileOps.downloadFile(file.id, file.name);
+                fileOps.downloadFile(file.id, file.name);
             }
         };
 
         const navigateFolder = (card) => {
             const folderId = card.dataset.folderId;
             const folderName = card.dataset.folderName;
-            window.app.breadcrumbPath.push({ id: folderId, name: folderName });
-            window.app.currentPath = folderId;
+            app.breadcrumbPath.push({ id: folderId, name: folderName });
+            app.currentPath = folderId;
             this.updateBreadcrumb();
-            window.loadFiles();
+            loadFiles();
         };
 
         const setContextTarget = (card, info) => {
             if (info.type === 'folder') {
-                window.app.contextMenuTargetFolder = {
+                app.contextMenuTargetFolder = {
                     id: info.id,
                     name: card.dataset.folderName,
                     parent_id: card.dataset.parentId || ''
                 };
             } else {
                 const fileData = info.data || self._items.get(info.id);
-                window.app.contextMenuTargetFile = {
+                app.contextMenuTargetFile = {
                     id: info.id,
                     name: card.dataset.fileName,
                     folder_id: card.dataset.folderId || '',
@@ -932,8 +952,8 @@ const ui = {
             }
 
             // shiftkey is used to complete selection
-            if (e.shiftKey && window.multiSelect) {
-                window.multiSelect.handleToggleItem(card, e);
+            if (e.shiftKey && multiSelect) {
+                multiSelect.handleToggleItem(card, e);
                 return;
             }
 
@@ -962,14 +982,14 @@ const ui = {
             setContextTarget(card, info);
             const menuId = info.type === 'folder' ? 'folder-context-menu' : 'file-context-menu';
             const menu = document.getElementById(menuId);
-            if (window.contextMenus && typeof window.contextMenus.syncFavoriteOptionLabels === 'function') {
-                window.contextMenus.syncFavoriteOptionLabels();
+            if (contextMenus && typeof contextMenus.syncFavoriteOptionLabels === 'function') {
+                contextMenus.syncFavoriteOptionLabels();
             }
-            if (window.contextMenus && typeof window.contextMenus.syncWopiOptionVisibility === 'function') {
-                window.contextMenus.syncWopiOptionVisibility().catch(() => {});
+            if (contextMenus && typeof contextMenus.syncWopiOptionVisibility === 'function') {
+                contextMenus.syncWopiOptionVisibility().catch(() => {});
             }
-            if (window.contextMenus && typeof window.contextMenus.syncAddToPlaylistOption === 'function') {
-                window.contextMenus.syncAddToPlaylistOption();
+            if (contextMenus && typeof contextMenus.syncAddToPlaylistOption === 'function') {
+                contextMenus.syncAddToPlaylistOption();
             }
             menu.style.left = `${e.pageX}px`;
             menu.style.top = `${e.pageY}px`;
@@ -1105,7 +1125,7 @@ const ui = {
             e.stopImmediatePropagation();
             e.preventDefault();
 
-            if (!window.favorites) return;
+            if (!favorites) return;
 
             const itemId = star.dataset.itemId;
             const itemType = star.dataset.itemType;
@@ -1115,15 +1135,15 @@ const ui = {
 
             if (isActive) {
                 this.setFavoriteVisualState(itemId, itemType, false);
-                window.favorites.removeFromFavorites(itemId, itemType);
+                favorites.removeFromFavorites(itemId, itemType);
             } else {
                 this.setFavoriteVisualState(itemId, itemType, true);
-                window.favorites.addToFavorites(itemId, itemName, itemType);
+                favorites.addToFavorites(itemId, itemName, itemType);
             }
 
             // Keep context-menu label in sync if available
-            if (window.contextMenus && typeof window.contextMenus.syncFavoriteOptionLabels === 'function') {
-                window.contextMenus.syncFavoriteOptionLabels();
+            if (contextMenus && typeof contextMenus.syncFavoriteOptionLabels === 'function') {
+                contextMenus.syncFavoriteOptionLabels();
             }
         });
     },
@@ -1142,8 +1162,8 @@ const ui = {
 
             // SVG icon path (after icons.js replacement)
             const svg = starBtn.querySelector('svg');
-            const filledPath = window.OxiIcons?.star;
-            const outlinePath = window.OxiIcons?.['star-outline'];
+            const filledPath = OxiIcons?.star;
+            const outlinePath = OxiIcons?.['star-outline'];
             const targetPath = isFavorite ? filledPath : outlinePath;
             if (svg && targetPath) {
                 const p = svg.querySelector('path');
@@ -1168,9 +1188,7 @@ const ui = {
                     inlineStar = document.createElement('i');
                     inlineStar.className = 'fas fa-star favorite-star-inline';
                     nameCell.appendChild(inlineStar);
-                    if (window.OxiIcons && typeof window.OxiIcons.replaceIconsInElement === 'function') {
-                        window.OxiIcons.replaceIconsInElement(nameCell);
-                    }
+                    replaceIconsInElement(nameCell);
                 } else if (!isFavorite && inlineStar) {
                     inlineStar.remove();
                 }
@@ -1190,8 +1208,8 @@ const ui = {
         el.dataset.folderName = folder.name;
         el.dataset.parentId = folder.parent_id || '';
 
-        const isFav = window.favorites?.isFavorite(folder.id, 'folder');
-        const formattedDate = window.formatDateTime(folder.modified_at);
+        const isFav = favorites?.isFavorite(folder.id, 'folder');
+        const formattedDate = formatDateTime(folder.modified_at);
 
         el.innerHTML = `
             <div class="checkbox-cell"><input type="checkbox" class="item-checkbox"></div>
@@ -1202,7 +1220,7 @@ const ui = {
                 <span>${escapeHtml(folder.name)}</span>
                 ${isFav ? '<i class="fas fa-star favorite-star-inline"></i>' : ''}
             </div>
-            <div class="type-cell">${window.i18n ? window.i18n.t('files.file_types.folder') : 'Folder'}</div>
+            <div class="type-cell">${i18n ? i18n.t('files.file_types.folder') : 'Folder'}</div>
             <div class="size-cell">--</div>
             <div class="date-cell">${formattedDate}</div>
             <div class="action-cell">
@@ -1213,7 +1231,7 @@ const ui = {
             </div>
         `;
 
-        if (window.app.currentPath !== '') {
+        if (app.currentPath !== '') {
             el.setAttribute('draggable', 'true');
         }
         this._bindStarClick(el);
@@ -1225,16 +1243,10 @@ const ui = {
         const iconClass = file.icon_class || this.getIconClass(file.name);
         const iconSpecialClass = file.icon_special_class || this.getIconSpecialClass(file.name);
         const cat = file.category || '';
-        const typeLabel = cat
-            ? window.i18n
-                ? window.i18n.t(`files.file_types.${cat.toLowerCase()}`) || cat
-                : cat
-            : window.i18n
-              ? window.i18n.t('files.file_types.document')
-              : 'Document';
-        const fileSize = file.size_formatted || window.formatFileSize(file.size);
-        const formattedDate = window.formatDateTime(file.modified_at);
-        const isFav = window.favorites?.isFavorite(file.id, 'file');
+        const typeLabel = cat ? (i18n ? i18n.t(`files.file_types.${cat.toLowerCase()}`) || cat : cat) : i18n ? i18n.t('files.file_types.document') : 'Document';
+        const fileSize = file.size_formatted || formatFileSize(file.size);
+        const formattedDate = formatDateTime(file.modified_at);
+        const isFav = favorites?.isFavorite(file.id, 'file');
 
         const el = document.createElement('div');
         el.className = 'file-item';
@@ -1293,7 +1305,7 @@ const ui = {
                 <div></div><!-- actions -->
             </div>`;
 
-        if (window.i18n?.translateElement) window.i18n.translateElement(filesList);
+        if (i18n?.translateElement) i18n.translateElement(filesList);
 
         filesList.classList.remove('hidden');
         filesContainerError?.classList.add('hidden');
@@ -1317,7 +1329,7 @@ const ui = {
         const filesList = document.getElementById('files-list');
         if (filesContainerError) filesContainerError.innerHTML = content;
 
-        if (window.i18n?.translateElement) window.i18n.translateElement(filesContainerError);
+        if (i18n?.translateElement) i18n.translateElement(filesContainerError);
 
         filesContainerError?.classList.remove('hidden');
         filesList?.classList.add('hidden');
@@ -1403,8 +1415,8 @@ const ui = {
  * Routes through the multiSelect module so batch actions know about selected items.
  */
 function toggleCardSelection(card, event) {
-    if (window.multiSelect) {
-        window.multiSelect.handleToggleItem(card, event);
+    if (multiSelect) {
+        multiSelect.handleToggleItem(card, event);
     } else {
         card.classList.toggle('selected');
     }
@@ -1435,14 +1447,14 @@ function showContextMenuAtElement(triggerElement, menuId) {
         top = rect.top - 4 + window.scrollY; // flip above if no room
     }
 
-    if (window.contextMenus && typeof window.contextMenus.syncFavoriteOptionLabels === 'function') {
-        window.contextMenus.syncFavoriteOptionLabels();
+    if (contextMenus && typeof contextMenus.syncFavoriteOptionLabels === 'function') {
+        contextMenus.syncFavoriteOptionLabels();
     }
-    if (window.contextMenus && typeof window.contextMenus.syncWopiOptionVisibility === 'function') {
-        window.contextMenus.syncWopiOptionVisibility().catch(() => {});
+    if (contextMenus && typeof contextMenus.syncWopiOptionVisibility === 'function') {
+        contextMenus.syncWopiOptionVisibility().catch(() => {});
     }
-    if (window.contextMenus && typeof window.contextMenus.syncAddToPlaylistOption === 'function') {
-        window.contextMenus.syncAddToPlaylistOption();
+    if (contextMenus && typeof contextMenus.syncAddToPlaylistOption === 'function') {
+        contextMenus.syncAddToPlaylistOption();
     }
 
     menu.style.left = `${left}px`;
@@ -1532,16 +1544,16 @@ function initRubberBandSelection() {
                 card.classList.add('selected');
 
                 // Sync with multiSelect module
-                if (window.multiSelect) {
-                    const info = window.multiSelect._extractInfo(card);
-                    if (info) window.multiSelect.select(info.id, info.name, info.type, info.parentId);
+                if (multiSelect) {
+                    const info = multiSelect._extractInfo(card);
+                    if (info) multiSelect.select(info.id, info.name, info.type, info.parentId);
                 }
             } else {
                 card.classList.remove('selected');
                 // Deselect from multiSelect module
-                if (window.multiSelect) {
-                    const info = window.multiSelect._extractInfo(card);
-                    if (info) window.multiSelect.deselect(info.id);
+                if (multiSelect) {
+                    const info = multiSelect._extractInfo(card);
+                    if (info) multiSelect.deselect(info.id);
                 }
             }
         });
@@ -1553,13 +1565,13 @@ function initRubberBandSelection() {
         const hadSelection = selRect.style.display === 'block';
         selRect.style.display = 'none';
         // Update the batch bar after rubber band selection completes
-        if (window.multiSelect) window.multiSelect._syncUI();
+        if (multiSelect) multiSelect._syncUI();
         // Suppress the click event that follows mouseup so the global
         // deselect handler doesn't immediately clear the selection.
         if (hadSelection) {
-            window.__rubberBandJustFinished = true;
+            __rubberBandJustFinished = true;
             requestAnimationFrame(() => {
-                window.__rubberBandJustFinished = false;
+                __rubberBandJustFinished = false;
             });
         }
     });
@@ -1572,11 +1584,6 @@ if (document.readyState === 'loading') {
     initRubberBandSelection();
 }
 
-// Expose helpers globally
-window.toggleCardSelection = toggleCardSelection;
-window.showContextMenuAtElement = showContextMenuAtElement;
-window.initRubberBandSelection = initRubberBandSelection;
-
 /**
  * Show a modern confirm dialog (replaces native confirm())
  * @param {Object} options
@@ -1588,9 +1595,9 @@ window.initRubberBandSelection = initRubberBandSelection;
  * @returns {Promise<boolean>} true if confirmed, false if cancelled
  */
 function showConfirmDialog({ title, message, confirmText, cancelText, danger = true } = {}) {
-    const ct = confirmText || (window.i18n ? window.i18n.t('actions.delete') : 'Delete');
-    const cc = cancelText || (window.i18n ? window.i18n.t('actions.cancel') : 'Cancel');
-    const t = title || (window.i18n ? window.i18n.t('dialogs.confirm_title') : 'Confirm action');
+    const ct = confirmText || (i18n ? i18n.t('actions.delete') : 'Delete');
+    const cc = cancelText || (i18n ? i18n.t('actions.cancel') : 'Cancel');
+    const t = title || (i18n ? i18n.t('dialogs.confirm_title') : 'Confirm action');
 
     return new Promise((resolve) => {
         // Remove any previous confirm dialog
@@ -1633,7 +1640,5 @@ function showConfirmDialog({ title, message, confirmText, cancelText, danger = t
         });
     });
 }
-window.showConfirmDialog = showConfirmDialog;
 
-// Expose UI module globally
-window.ui = ui;
+export { initRubberBandSelection, showConfirmDialog, showContextMenuAtElement, toggleCardSelection, ui };
diff --git a/static/js/app/uiFileTypes.js b/static/js/app/uiFileTypes.js
index dd1f5761..d547df46 100644
--- a/static/js/app/uiFileTypes.js
+++ b/static/js/app/uiFileTypes.js
@@ -3,6 +3,8 @@
  * Isolated icon and preview classification helpers used by ui.js.
  */
 
+import { isTextViewable } from '../core/formatters.js';
+
 const uiFileTypes = {
     // TODO: 'd better to use a canViw() method in inlineViewer
     isViewableFile(file) {
@@ -11,7 +13,7 @@ const uiFileTypes = {
         if (file.mime_type === 'application/pdf') return true;
         if (file.mime_type.startsWith('audio/')) return true;
         if (file.mime_type.startsWith('video/')) return true;
-        return window.isTextViewable ? window.isTextViewable(file.mime_type) : false;
+        return isTextViewable(file.mime_type);
     },
 
     getIconClass(fileName) {
@@ -170,4 +172,4 @@ const uiFileTypes = {
     }
 };
 
-window.uiFileTypes = uiFileTypes;
+export { uiFileTypes };
diff --git a/static/js/app/uiNotifications.js b/static/js/app/uiNotifications.js
index 76244219..70473ddc 100644
--- a/static/js/app/uiNotifications.js
+++ b/static/js/app/uiNotifications.js
@@ -3,9 +3,11 @@
  * Isolates notification rendering policy from ui.js.
  */
 
+import { notifications } from '../core/notifications.js';
+
 const uiNotifications = {
     show(title, message) {
-        if (window.notifications && typeof window.notifications.addNotification === 'function') {
+        if (notifications && typeof notifications.addNotification === 'function') {
             const normalizedTitle = String(title || '').toLowerCase();
             let icon = 'fa-info-circle';
             let iconClass = 'upload';
@@ -27,7 +29,7 @@ const uiNotifications = {
                 iconClass = 'success';
             }
 
-            window.notifications.addNotification({
+            notifications.addNotification({
                 icon,
                 iconClass,
                 title: title || '',
@@ -58,4 +60,4 @@ const uiNotifications = {
     }
 };
 
-window.uiNotifications = uiNotifications;
+export { uiNotifications };
diff --git a/static/js/app/userMenu.js b/static/js/app/userMenu.js
index 9096c26f..84dadeb9 100644
--- a/static/js/app/userMenu.js
+++ b/static/js/app/userMenu.js
@@ -2,6 +2,11 @@
  * User menu, profile modal and logout logic
  */
 
+import { getCsrfHeaders } from '../core/csrf.js';
+import { formatFileSize, formatQuotaSize } from '../core/formatters.js';
+import { i18n } from '../core/i18n.js';
+import { ui } from './ui.js';
+
 function setupUserMenu() {
     const wrapper = document.getElementById('user-menu-wrapper');
     const avatarBtn = document.getElementById('user-avatar-btn');
@@ -102,7 +107,7 @@ function setupUserMenu() {
                 }
             }
 
-            window.ui.showNotification(newIsDark ? '🌙' : '☀️', newIsDark ? 'Dark mode enabled' : 'Light mode enabled');
+            ui.showNotification(newIsDark ? '🌙' : '☀️', newIsDark ? 'Dark mode enabled' : 'Light mode enabled');
         });
     }
 
@@ -173,8 +178,8 @@ function updateUserMenuData() {
 
     if (storageFill) storageFill.style.width = `${percentage}%`;
     if (storageText) {
-        const used = window.formatFileSize(usedBytes);
-        const total = window.formatQuotaSize(quotaBytes);
+        const used = formatFileSize(usedBytes);
+        const total = formatQuotaSize(quotaBytes);
         storageText.textContent = `${quotaBytes > 0 ? `${percentage}% · ` : ''}${used} / ${total}`;
     }
 }
@@ -206,7 +211,7 @@ function showUserProfileModal() {
     const percentage = quotaBytes > 0 ? Math.min(Math.round((usedBytes / quotaBytes) * 100), 100) : 0;
     const barColor = percentage > 90 ? '#ef4444' : percentage > 70 ? '#f59e0b' : '#22c55e';
 
-    const t = (key, fallback) => (window.i18n?.t ? window.i18n.t(key) || fallback : fallback);
+    const t = (key, fallback) => (i18n?.t ? i18n.t(key) || fallback : fallback);
 
     const existing = document.getElementById('profile-modal-overlay');
     if (existing) existing.remove();
@@ -229,7 +234,7 @@ function showUserProfileModal() {
                 <div class="about-modal-bar-bg">
                     <div class="about-modal-bar-fill" id="about-bar-fill"></div>
                 </div>
-                <div class="about-modal-bar-text">${percentage}% · ${window.formatFileSize(usedBytes)} / ${window.formatQuotaSize(quotaBytes)}</div>
+                <div class="about-modal-bar-text">${percentage}% · ${formatFileSize(usedBytes)} / ${formatQuotaSize(quotaBytes)}</div>
             </div>
             <div class="about-modal-footer">
                 <button id="profile-modal-close" class="about-modal-close-btn">${t('actions.close', 'Close')}</button>
@@ -283,6 +288,4 @@ async function logout() {
     window.location.href = '/login';
 }
 
-window.setupUserMenu = setupUserMenu;
-window.showUserProfileModal = showUserProfileModal;
-window.logout = logout;
+export { logout, setupUserMenu, showUserProfileModal };
diff --git a/static/js/core/csrf.js b/static/js/core/csrf.js
index c8c3159e..b449c277 100644
--- a/static/js/core/csrf.js
+++ b/static/js/core/csrf.js
@@ -13,14 +13,14 @@
  * HttpOnly cookies.
  */
 
-// eslint-disable-next-line no-unused-vars
 function getCsrfToken() {
     const match = document.cookie.split('; ').find((row) => row.startsWith('oxicloud_csrf='));
     return match ? match.split('=')[1] : '';
 }
 
-// biome-ignore lint/correctness/noUnusedVariables: global function
 function getCsrfHeaders() {
     const token = getCsrfToken();
     return token ? { 'X-CSRF-Token': token } : {};
 }
+
+export { getCsrfHeaders, getCsrfToken };
diff --git a/static/js/core/formatters.js b/static/js/core/formatters.js
index 774a65cf..72671db6 100644
--- a/static/js/core/formatters.js
+++ b/static/js/core/formatters.js
@@ -65,9 +65,4 @@ function isTextViewable(mimeType) {
     return textTypes.includes(mimeType);
 }
 
-window.escapeHtml = escapeHtml;
-window.formatFileSize = formatFileSize;
-window.formatQuotaSize = formatQuotaSize;
-window.formatDateTime = formatDateTime;
-window.formatDateShort = formatDateShort;
-window.isTextViewable = isTextViewable;
+export { escapeHtml, formatDateShort, formatDateTime, formatFileSize, formatQuotaSize, isTextViewable };
diff --git a/static/js/core/i18n.js b/static/js/core/i18n.js
index 01c9d28f..c46ad23a 100644
--- a/static/js/core/i18n.js
+++ b/static/js/core/i18n.js
@@ -314,8 +314,7 @@ function safeT(key, params = {}) {
     return interpolate(value, params);
 }
 
-// Export functions for use in other modules
-window.i18n = {
+export const i18n = {
     t: safeT,
     setLocale,
     getCurrentLocale,
diff --git a/static/js/core/icons.js b/static/js/core/icons.js
index fcae309c..41efa5a4 100644
--- a/static/js/core/icons.js
+++ b/static/js/core/icons.js
@@ -483,9 +483,8 @@ function replaceIconsInElement(container) {
 }
 
 // ── Expose globally ────────────────────────────────────────────
-window.oxiIcon = oxiIcon;
-window.replaceIconsInElement = replaceIconsInElement;
-window.OxiIcons = _ICONS;
+export { oxiIcon, replaceIconsInElement };
+export const OxiIcons = _ICONS;
 
 // ── Auto-replace: MutationObserver bridge ──────────────────────
 // Watches the DOM for new <i class="fa-..."> elements and converts them
diff --git a/static/js/core/languageSelector.js b/static/js/core/languageSelector.js
index cad1bfd4..df012709 100644
--- a/static/js/core/languageSelector.js
+++ b/static/js/core/languageSelector.js
@@ -1,3 +1,6 @@
+import { ALL_LANGUAGES } from '../features/auth/auth.js';
+import { i18n } from './i18n.js';
+
 /**
  * Language Selector Component for OxiCloud
  * Custom styled dropdown with flags
@@ -63,7 +66,7 @@ function createLanguageSelector(containerId = 'language-selector') {
 
     // Get current language
     const languages = getAvailableLanguages();
-    const currentLocale = window.i18n ? window.i18n.getCurrentLocale() : 'en';
+    const currentLocale = i18n ? i18n.getCurrentLocale() : 'en';
     const currentLang = languages.find((l) => l.code === currentLocale) || languages[0];
 
     // Set initial HTML attributes
@@ -183,8 +186,8 @@ function closeDropdown(container) {
  */
 async function selectLanguage(langCode, container) {
     // Update i18n if available
-    if (window.i18n) {
-        await window.i18n.setLocale(langCode);
+    if (i18n) {
+        await i18n.setLocale(langCode);
     }
 
     // Update HTML lang attribute and dir for RTL languages
diff --git a/static/js/core/modal.js b/static/js/core/modal.js
index f5682336..4c454c5f 100644
--- a/static/js/core/modal.js
+++ b/static/js/core/modal.js
@@ -1,3 +1,6 @@
+import { i18n } from './i18n.js';
+import { replaceIconsInElement } from './icons.js';
+
 /**
  * Modal System for OxiCloud
  * Provides modern, styled modals to replace browser prompts/alerts
@@ -86,8 +89,8 @@ const Modal = {
                 iconContainer.innerHTML = `<i id="modal-icon" class="fas ${icon}"></i>`;
                 this.icon = document.getElementById('modal-icon');
                 // Let icons.js convert it to SVG
-                if (window.replaceIconsInElement) {
-                    window.replaceIconsInElement(iconContainer);
+                if (replaceIconsInElement) {
+                    replaceIconsInElement(iconContainer);
                     this.icon = document.getElementById('modal-icon');
                 }
             }
@@ -99,14 +102,14 @@ const Modal = {
             // Set button text (use i18n if available)
             if (confirmText) {
                 this.confirmBtn.textContent = confirmText;
-            } else if (window.i18n) {
-                this.confirmBtn.textContent = window.i18n.t('actions.confirm');
+            } else if (i18n) {
+                this.confirmBtn.textContent = i18n.t('actions.confirm');
             }
 
             if (cancelText) {
                 this.cancelBtn.textContent = cancelText;
-            } else if (window.i18n) {
-                this.cancelBtn.textContent = window.i18n.t('actions.cancel');
+            } else if (i18n) {
+                this.cancelBtn.textContent = i18n.t('actions.cancel');
             }
 
             // Set callbacks
@@ -126,7 +129,7 @@ const Modal = {
      * @returns {Promise<string|null>}
      */
     promptNewFolder() {
-        const t = window.i18n ? window.i18n.t.bind(window.i18n) : (k) => k;
+        const t = i18n ? i18n.t.bind(i18n) : (k) => k;
 
         return this.prompt({
             title: t('dialogs.new_folder_title') || 'New folder',
@@ -144,7 +147,7 @@ const Modal = {
      * @returns {Promise<string|null>}
      */
     promptRename(currentName, isFolder = false) {
-        const t = window.i18n ? window.i18n.t.bind(window.i18n) : (k) => k;
+        const t = i18n ? i18n.t.bind(i18n) : (k) => k;
 
         // For files, we want to select only the name part (without extension)
         this._selectNameOnly = !isFolder;
@@ -232,4 +235,4 @@ document.addEventListener('DOMContentLoaded', () => {
 });
 
 // Export for use in other modules
-window.Modal = Modal;
+export { Modal };
diff --git a/static/js/core/notifications.js b/static/js/core/notifications.js
index 86315ccc..59878ee6 100644
--- a/static/js/core/notifications.js
+++ b/static/js/core/notifications.js
@@ -1,3 +1,5 @@
+import { i18n } from './i18n.js';
+
 /**
  * OxiCloud – Notification Bell Module
  *
@@ -5,7 +7,7 @@
  * in the top-bar. Upload progress, quota errors, and general messages all
  * go through this module.
  *
- * Public API (on window.notifications):
+ * Public API (exported as `notifications`):
  *   addUploadBatch(totalFiles)       → batchId
  *   updateFile(batchId, fileName, pct, status)
  *   finishBatch(batchId, successCount, totalFiles)
@@ -147,7 +149,7 @@ const notifications = (() => {
         item.className = 'notif-item';
         item.id = batchId;
 
-        const t = window.i18n?.t || ((k) => k);
+        const t = i18n?.t || ((k) => k);
         const uploadingText = folderName ? `📁 ${t('upload.uploading')} ${_esc(folderName)}…` : t('upload.uploading');
         const filesLabel = t('upload.files');
 
@@ -252,7 +254,7 @@ const notifications = (() => {
         const pctEl = $(`${batchId}-pct`);
         const statsEl = $(`${batchId}-stats`);
 
-        const t = window.i18n?.t || ((k) => k);
+        const t = i18n?.t || ((k) => k);
         const filesLabel = t('upload.files');
 
         if (fillEl) fillEl.style.width = `${pctVal}%`;
@@ -280,7 +282,7 @@ const notifications = (() => {
         const curEl = $(`${batchId}-current`);
         if (curEl) curEl.textContent = '';
 
-        const t = window.i18n?.t || ((k) => k);
+        const t = i18n?.t || ((k) => k);
         const completeText = t('upload.complete', {
             count: successCount,
             total: totalFiles
@@ -351,4 +353,4 @@ const notifications = (() => {
     };
 })();
 
-window.notifications = notifications;
+export { notifications };
diff --git a/static/js/features/auth/auth.js b/static/js/features/auth/auth.js
index 13b007cf..30c424f8 100644
--- a/static/js/features/auth/auth.js
+++ b/static/js/features/auth/auth.js
@@ -3,6 +3,9 @@
  * Handles login, registration, and admin setup
  */
 
+import { getCsrfHeaders } from '../../core/csrf.js';
+import { i18n } from '../../core/i18n.js';
+
 // API endpoints
 const API_URL = '/api/auth';
 const LOGIN_ENDPOINT = `${API_URL}/login`;
@@ -112,7 +115,7 @@ const LANGUAGE_TEXTS = {
 
 // Complete language registry — add new languages here, they'll appear automatically
 // `popular: true` languages show as cards on the main screen, the rest in the modal
-const ALL_LANGUAGES = [
+export const ALL_LANGUAGES = [
     {
         code: 'en',
         name: 'English',
@@ -509,8 +512,8 @@ function initLanguageSelector() {
         localStorage.setItem(FIRST_RUN_KEY, 'true');
 
         // Update i18n if available
-        if (window.i18n?.setLocale) {
-            await window.i18n.setLocale(selectedLanguage);
+        if (i18n?.setLocale) {
+            await i18n.setLocale(selectedLanguage);
         }
 
         // Hide language panel
@@ -632,7 +635,7 @@ async function configureOidcLoginUI() {
         // Update button text with provider name
         const btnTextEl = oidcBtn.querySelector('span');
         if (btnTextEl && oidcInfo.provider_name) {
-            const template = window.i18n?.t ? window.i18n.t('auth.sso_login_provider') : 'Sign in with {{provider}}';
+            const template = i18n?.t ? i18n.t('auth.sso_login_provider') : 'Sign in with {{provider}}';
             btnTextEl.textContent = template.replace('{{provider}}', oidcInfo.provider_name);
         }
 
@@ -669,7 +672,6 @@ function initLoginElements() {
         return false;
     }
 
-    languagePanel = document.getElementById('language-panel');
     loginPanel = document.getElementById('login-panel');
     registerPanel = document.getElementById('register-panel');
     adminSetupPanel = document.getElementById('admin-setup-panel');
@@ -940,7 +942,7 @@ if (isLoginPage && registerForm) {
 
         // Validate passwords match
         if (password !== confirmPassword) {
-            const errorMsg = window.i18n ? window.i18n.t('auth.passwords_mismatch') : 'Passwords do not match';
+            const errorMsg = i18n ? i18n.t('auth.passwords_mismatch') : 'Passwords do not match';
             registerError.textContent = errorMsg;
             registerError.style.display = 'block';
             return;
@@ -950,7 +952,7 @@ if (isLoginPage && registerForm) {
             await register(username, email, password);
 
             // Show success message
-            const successMsg = window.i18n ? window.i18n.t('auth.account_success') : 'Account created successfully! You can now log in.';
+            const successMsg = i18n ? i18n.t('auth.account_success') : 'Account created successfully! You can now log in.';
             registerSuccess.textContent = successMsg;
             registerSuccess.style.display = 'block';
 
@@ -963,7 +965,7 @@ if (isLoginPage && registerForm) {
                 hidePanel(registerPanel);
             }, 2000);
         } catch (error) {
-            const errorMsg = window.i18n ? window.i18n.t('auth.admin_create_error') : 'Error registering account';
+            const errorMsg = i18n ? i18n.t('auth.admin_create_error') : 'Error registering account';
             registerError.textContent = error.message || errorMsg;
             registerError.style.display = 'block';
         }
@@ -986,7 +988,7 @@ if (isLoginPage && adminSetupForm) {
 
         // Validate passwords match
         if (password !== confirmPassword) {
-            const errorMsg = window.i18n ? window.i18n.t('auth.passwords_mismatch') : 'Passwords do not match';
+            const errorMsg = i18n ? i18n.t('auth.passwords_mismatch') : 'Passwords do not match';
             adminSetupError.textContent = errorMsg;
             adminSetupError.style.display = 'block';
             return;
@@ -1011,7 +1013,7 @@ if (isLoginPage && adminSetupForm) {
             await response.json();
 
             // Show success message in the GUI instead of alert
-            const successMsg = window.i18n ? window.i18n.t('auth.admin_success') : 'Admin account created successfully! You can now log in.';
+            const successMsg = i18n ? i18n.t('auth.admin_success') : 'Admin account created successfully! You can now log in.';
 
             if (adminSetupSuccess) {
                 adminSetupSuccess.textContent = successMsg;
@@ -1025,7 +1027,7 @@ if (isLoginPage && adminSetupForm) {
                 if (adminSetupSuccess) adminSetupSuccess.style.display = 'none';
             }, 2000);
         } catch (error) {
-            const errorMsg = window.i18n ? window.i18n.t('auth.admin_create_error') : 'Error creating admin account';
+            const errorMsg = i18n ? i18n.t('auth.admin_create_error') : 'Error creating admin account';
             adminSetupError.textContent = error.message || errorMsg;
             adminSetupError.style.display = 'block';
         }
diff --git a/static/js/features/files/contextMenus.js b/static/js/features/files/contextMenus.js
index 15422b50..e73e28fa 100644
--- a/static/js/features/files/contextMenus.js
+++ b/static/js/features/files/contextMenus.js
@@ -3,6 +3,23 @@
  * This file handles context menus and dialog functionality
  */
 
+import { resolveHomeFolder } from '../../app/authSession.js';
+import { loadFiles } from '../../app/filesView.js';
+import { app } from '../../app/state.js';
+import { showConfirmDialog, ui } from '../../app/ui.js';
+import { getCsrfHeaders } from '../../core/csrf.js';
+import { escapeHtml } from '../../core/formatters.js';
+import { i18n } from '../../core/i18n.js';
+import { favorites } from '../library/favorites.js';
+import { musicView } from '../library/music.js';
+import { fileSharing } from '../sharing/fileSharing.js';
+import { fileOps } from './fileOperations.js';
+import { inlineViewer } from './inlineViewer.js';
+import { multiSelect } from './multiSelect.js';
+import { wopiEditor } from './wopiEditor.js';
+
+let _moveDialogEscapeHandler = null;
+
 // Context Menus Module
 const contextMenus = {
     _setFavoriteOptionLabel(optionId, isFavorite) {
@@ -10,11 +27,7 @@ const contextMenus = {
         if (!option) return;
         const label = option.querySelector('span');
         if (!label) return;
-        label.textContent = window.i18n
-            ? window.i18n.t(isFavorite ? 'actions.unfavorite' : 'actions.favorite')
-            : isFavorite
-              ? 'Remove from favorites'
-              : 'Add to favorites';
+        label.textContent = i18n ? i18n.t(isFavorite ? 'actions.unfavorite' : 'actions.favorite') : isFavorite ? 'Remove from favorites' : 'Add to favorites';
     },
 
     /**
@@ -25,28 +38,28 @@ const contextMenus = {
         const wopiEditTab = document.getElementById('wopi-edit-file-tab-option');
         if (!wopiEdit || !wopiEditTab) return;
 
-        const targetFile = window.app?.contextMenuTargetFile;
+        const targetFile = app?.contextMenuTargetFile;
         // Don't show WOPI editor for image files - they should use inline preview
         const isImage = targetFile?.mime_type?.startsWith('image/');
-        const show = targetFile && !isImage && window.wopiEditor && (await window.wopiEditor.canEdit(targetFile.name));
+        const show = targetFile && !isImage && wopiEditor && (await wopiEditor.canEdit(targetFile.name));
 
         wopiEdit.classList.toggle('hidden', !show);
         wopiEditTab.classList.toggle('hidden', !show);
     },
 
     syncFavoriteOptionLabels() {
-        if (!window.favorites) return;
+        if (!favorites) return;
 
-        const targetFile = window.app?.contextMenuTargetFile;
-        const targetFolder = window.app?.contextMenuTargetFolder;
+        const targetFile = app?.contextMenuTargetFile;
+        const targetFolder = app?.contextMenuTargetFolder;
 
         if (targetFile) {
-            const isFav = window.favorites.isFavorite(targetFile.id, 'file');
+            const isFav = favorites.isFavorite(targetFile.id, 'file');
             this._setFavoriteOptionLabel('favorite-file-option', isFav);
         }
 
         if (targetFolder) {
-            const isFav = window.favorites.isFavorite(targetFolder.id, 'folder');
+            const isFav = favorites.isFavorite(targetFolder.id, 'folder');
             this._setFavoriteOptionLabel('favorite-folder-option', isFav);
         }
     },
@@ -55,7 +68,7 @@ const contextMenus = {
         const option = document.getElementById('add-to-playlist-option');
         if (!option) return;
 
-        const targetFile = window.app?.contextMenuTargetFile;
+        const targetFile = app?.contextMenuTargetFile;
         if (targetFile) {
             const isAudio = targetFile.mime_type?.startsWith('audio/');
             option.classList.toggle('hidden', !isAudio);
@@ -70,172 +83,172 @@ const contextMenus = {
     assignMenuEvents() {
         // Folder context menu options
         document.getElementById('download-folder-option').addEventListener('click', () => {
-            if (window.app.contextMenuTargetFolder) {
-                window.fileOps.downloadFolder(window.app.contextMenuTargetFolder.id, window.app.contextMenuTargetFolder.name);
+            if (app.contextMenuTargetFolder) {
+                fileOps.downloadFolder(app.contextMenuTargetFolder.id, app.contextMenuTargetFolder.name);
             }
-            window.ui.closeContextMenu();
+            ui.closeContextMenu();
         });
 
         document.getElementById('favorite-folder-option').addEventListener('click', async () => {
-            if (window.app.contextMenuTargetFolder) {
-                const folder = window.app.contextMenuTargetFolder;
+            if (app.contextMenuTargetFolder) {
+                const folder = app.contextMenuTargetFolder;
 
                 // Check if folder is already in favorites to toggle
-                if (window.favorites?.isFavorite(folder.id, 'folder')) {
+                if (favorites?.isFavorite(folder.id, 'folder')) {
                     // Remove from favorites
-                    const ok = await window.favorites.removeFromFavorites(folder.id, 'folder');
-                    if (ok && window.ui && typeof window.ui.setFavoriteVisualState === 'function') {
-                        window.ui.setFavoriteVisualState(folder.id, 'folder', false);
+                    const ok = await favorites.removeFromFavorites(folder.id, 'folder');
+                    if (ok && ui && typeof ui.setFavoriteVisualState === 'function') {
+                        ui.setFavoriteVisualState(folder.id, 'folder', false);
                     }
                 } else {
                     // Add to favorites
-                    const ok = await window.favorites.addToFavorites(folder.id, folder.name, 'folder', folder.parent_id);
-                    if (ok && window.ui && typeof window.ui.setFavoriteVisualState === 'function') {
-                        window.ui.setFavoriteVisualState(folder.id, 'folder', true);
+                    const ok = await favorites.addToFavorites(folder.id, folder.name, 'folder', folder.parent_id);
+                    if (ok && ui && typeof ui.setFavoriteVisualState === 'function') {
+                        ui.setFavoriteVisualState(folder.id, 'folder', true);
                     }
                 }
                 this.syncFavoriteOptionLabels();
             }
-            window.ui.closeContextMenu();
+            ui.closeContextMenu();
         });
 
         document.getElementById('rename-folder-option').addEventListener('click', () => {
-            if (window.app.contextMenuTargetFolder) {
-                this.showRenameDialog(window.app.contextMenuTargetFolder);
+            if (app.contextMenuTargetFolder) {
+                this.showRenameDialog(app.contextMenuTargetFolder);
             }
-            window.ui.closeContextMenu();
+            ui.closeContextMenu();
         });
 
         document.getElementById('move-folder-option').addEventListener('click', () => {
-            if (window.app.contextMenuTargetFolder) {
-                this.showMoveDialog(window.app.contextMenuTargetFolder, 'folder');
+            if (app.contextMenuTargetFolder) {
+                this.showMoveDialog(app.contextMenuTargetFolder, 'folder');
             }
-            window.ui.closeContextMenu();
+            ui.closeContextMenu();
         });
 
         document.getElementById('share-folder-option').addEventListener('click', () => {
-            const folder = window.app.contextMenuTargetFolder;
+            const folder = app.contextMenuTargetFolder;
             if (folder) {
                 this.showShareDialog(folder, 'folder');
             }
-            window.ui.closeContextMenu();
+            ui.closeContextMenu();
         });
 
         document.getElementById('delete-folder-option').addEventListener('click', async () => {
-            const folder = window.app.contextMenuTargetFolder;
-            window.ui.closeContextMenu();
+            const folder = app.contextMenuTargetFolder;
+            ui.closeContextMenu();
             if (folder) {
-                await window.fileOps.deleteFolder(folder.id, folder.name);
+                await fileOps.deleteFolder(folder.id, folder.name);
             }
         });
 
         // File context menu options
         document.getElementById('view-file-option').addEventListener('click', () => {
-            if (window.app.contextMenuTargetFile) {
+            if (app.contextMenuTargetFile) {
                 // Capture reference before context menu cleanup nullifies it
-                const file = window.app.contextMenuTargetFile;
+                const file = app.contextMenuTargetFile;
                 fetch(`/api/files/${file.id}?metadata=true`, {
                     credentials: 'same-origin'
                 })
                     .then((response) => response.json())
                     .then((fileDetails) => {
                         // Check if viewable file type (images, PDFs, text files)
-                        if (window.ui?.isViewableFile(fileDetails)) {
+                        if (ui?.isViewableFile(fileDetails)) {
                             // Open with inline viewer
-                            if (window.inlineViewer) {
-                                window.inlineViewer.openFile(fileDetails);
+                            if (inlineViewer) {
+                                inlineViewer.openFile(fileDetails);
                             } else {
                                 // If no viewer is available, download directly
-                                window.fileOps.downloadFile(file.id, file.name);
+                                fileOps.downloadFile(file.id, file.name);
                             }
                         } else {
                             // For non-viewable files, download
-                            window.fileOps.downloadFile(file.id, file.name);
+                            fileOps.downloadFile(file.id, file.name);
                         }
                     })
                     .catch((error) => {
                         console.error('Error fetching file details:', error);
                         // On error, fallback to download
-                        window.fileOps.downloadFile(file.id, file.name);
+                        fileOps.downloadFile(file.id, file.name);
                     });
             }
-            window.ui.closeFileContextMenu();
+            ui.closeFileContextMenu();
         });
 
         document.getElementById('wopi-edit-file-option').addEventListener('click', () => {
-            if (window.app.contextMenuTargetFile) {
-                const file = window.app.contextMenuTargetFile;
-                window.wopiEditor.openInModal(file.id, file.name, 'edit');
+            if (app.contextMenuTargetFile) {
+                const file = app.contextMenuTargetFile;
+                wopiEditor.openInModal(file.id, file.name, 'edit');
             }
-            window.ui.closeFileContextMenu();
+            ui.closeFileContextMenu();
         });
 
         document.getElementById('wopi-edit-file-tab-option').addEventListener('click', () => {
-            if (window.app.contextMenuTargetFile) {
-                const file = window.app.contextMenuTargetFile;
-                window.wopiEditor.openInTab(file.id, file.name, 'edit');
+            if (app.contextMenuTargetFile) {
+                const file = app.contextMenuTargetFile;
+                wopiEditor.openInTab(file.id, file.name, 'edit');
             }
-            window.ui.closeFileContextMenu();
+            ui.closeFileContextMenu();
         });
 
         document.getElementById('download-file-option').addEventListener('click', () => {
-            if (window.app.contextMenuTargetFile) {
-                window.fileOps.downloadFile(window.app.contextMenuTargetFile.id, window.app.contextMenuTargetFile.name);
+            if (app.contextMenuTargetFile) {
+                fileOps.downloadFile(app.contextMenuTargetFile.id, app.contextMenuTargetFile.name);
             }
-            window.ui.closeFileContextMenu();
+            ui.closeFileContextMenu();
         });
 
         document.getElementById('favorite-file-option').addEventListener('click', async () => {
-            if (window.app.contextMenuTargetFile) {
-                const file = window.app.contextMenuTargetFile;
+            if (app.contextMenuTargetFile) {
+                const file = app.contextMenuTargetFile;
 
                 // Check if file is already in favorites to toggle
-                if (window.favorites?.isFavorite(file.id, 'file')) {
+                if (favorites?.isFavorite(file.id, 'file')) {
                     // Remove from favorites
-                    const ok = await window.favorites.removeFromFavorites(file.id, 'file');
-                    if (ok && window.ui && typeof window.ui.setFavoriteVisualState === 'function') {
-                        window.ui.setFavoriteVisualState(file.id, 'file', false);
+                    const ok = await favorites.removeFromFavorites(file.id, 'file');
+                    if (ok && ui && typeof ui.setFavoriteVisualState === 'function') {
+                        ui.setFavoriteVisualState(file.id, 'file', false);
                     }
                 } else {
                     // Add to favorites
-                    const ok = await window.favorites.addToFavorites(file.id, file.name, 'file', file.folder_id);
-                    if (ok && window.ui && typeof window.ui.setFavoriteVisualState === 'function') {
-                        window.ui.setFavoriteVisualState(file.id, 'file', true);
+                    const ok = await favorites.addToFavorites(file.id, file.name, 'file', file.folder_id);
+                    if (ok && ui && typeof ui.setFavoriteVisualState === 'function') {
+                        ui.setFavoriteVisualState(file.id, 'file', true);
                     }
                 }
                 this.syncFavoriteOptionLabels();
             }
-            window.ui.closeFileContextMenu();
+            ui.closeFileContextMenu();
         });
 
         document.getElementById('rename-file-option').addEventListener('click', () => {
-            if (window.app.contextMenuTargetFile) {
-                this.showRenameFileDialog(window.app.contextMenuTargetFile);
+            if (app.contextMenuTargetFile) {
+                this.showRenameFileDialog(app.contextMenuTargetFile);
             }
-            window.ui.closeFileContextMenu();
+            ui.closeFileContextMenu();
         });
 
         document.getElementById('move-file-option').addEventListener('click', () => {
-            if (window.app.contextMenuTargetFile) {
-                this.showMoveDialog(window.app.contextMenuTargetFile, 'file');
+            if (app.contextMenuTargetFile) {
+                this.showMoveDialog(app.contextMenuTargetFile, 'file');
             }
-            window.ui.closeFileContextMenu();
+            ui.closeFileContextMenu();
         });
 
         document.getElementById('share-file-option').addEventListener('click', () => {
-            const file = window.app.contextMenuTargetFile;
+            const file = app.contextMenuTargetFile;
             if (file) {
                 this.showShareDialog(file, 'file');
             }
-            window.ui.closeFileContextMenu();
+            ui.closeFileContextMenu();
         });
 
         document.getElementById('add-to-playlist-option').addEventListener('click', () => {
-            const file = window.app.contextMenuTargetFile;
+            const file = app.contextMenuTargetFile;
             if (file) {
                 this.showPlaylistDialog(file);
             }
-            window.ui.closeFileContextMenu();
+            ui.closeFileContextMenu();
         });
 
         document.getElementById('playlist-add-btn').addEventListener('click', () => {
@@ -243,10 +256,10 @@ const contextMenus = {
         });
 
         document.getElementById('delete-file-option').addEventListener('click', async () => {
-            const file = window.app.contextMenuTargetFile;
-            window.ui.closeFileContextMenu();
+            const file = app.contextMenuTargetFile;
+            ui.closeFileContextMenu();
             if (file) {
-                await window.fileOps.deleteFile(file.id, file.name);
+                await fileOps.deleteFile(file.id, file.name);
             }
         });
 
@@ -279,43 +292,43 @@ const contextMenus = {
         // Store handler reference to avoid duplicate listeners
         // Note: We don't use stopPropagation because all Escape handlers are on document level
         // Each handler checks its own state, so multiple dialogs can be closed with multiple Escape presses
-        if (!window._moveDialogEscapeHandler) {
-            window._moveDialogEscapeHandler = (e) => {
+        if (!_moveDialogEscapeHandler) {
+            _moveDialogEscapeHandler = (e) => {
                 if (e.key === 'Escape' && moveFileDialog.style.display === 'flex') {
                     this.closeMoveDialog();
                 }
             };
-            document.addEventListener('keydown', window._moveDialogEscapeHandler);
+            document.addEventListener('keydown', _moveDialogEscapeHandler);
         }
 
         // Copy button handler
         copyConfirmBtn.addEventListener('click', async () => {
             // Batch copy mode (from multiSelect)
-            if (window.app.moveDialogMode === 'batch' && window.multiSelect) {
-                const targetId = window.app.selectedTargetFolderId;
-                const items = window.app.batchMoveItems || [];
+            if (app.moveDialogMode === 'batch' && multiSelect) {
+                const targetId = app.selectedTargetFolderId;
+                const items = app.batchMoveItems || [];
 
                 const fileIds = items.filter((i) => i.type === 'file').map((i) => i.id);
                 const folderIds = items.filter((i) => i.type === 'folder').map((i) => i.id);
 
-                const result = await window.fileOps.batchCopy(fileIds, folderIds, targetId);
+                const result = await fileOps.batchCopy(fileIds, folderIds, targetId);
 
                 this.closeMoveDialog();
-                window.multiSelect.clear();
-                window.loadFiles();
+                multiSelect.clear();
+                loadFiles();
 
-                window.multiSelect.showBatchResult('copy', result);
+                multiSelect.showBatchResult('copy', result);
                 return;
             }
 
             // Single item copy
-            if (window.app.moveDialogMode === 'file' && window.app.contextMenuTargetFile) {
-                const success = await window.fileOps.copyFile(window.app.contextMenuTargetFile.id, window.app.selectedTargetFolderId);
+            if (app.moveDialogMode === 'file' && app.contextMenuTargetFile) {
+                const success = await fileOps.copyFile(app.contextMenuTargetFile.id, app.selectedTargetFolderId);
                 if (success) {
                     this.closeMoveDialog();
                 }
-            } else if (window.app.moveDialogMode === 'folder' && window.app.contextMenuTargetFolder) {
-                const success = await window.fileOps.copyFolder(window.app.contextMenuTargetFolder.id, window.app.selectedTargetFolderId);
+            } else if (app.moveDialogMode === 'folder' && app.contextMenuTargetFolder) {
+                const success = await fileOps.copyFolder(app.contextMenuTargetFolder.id, app.selectedTargetFolderId);
                 if (success) {
                     this.closeMoveDialog();
                 }
@@ -324,30 +337,30 @@ const contextMenus = {
 
         moveConfirmBtn.addEventListener('click', async () => {
             // Batch move mode (from multiSelect)
-            if (window.app.moveDialogMode === 'batch' && window.multiSelect) {
-                const targetId = window.app.selectedTargetFolderId;
-                const items = window.app.batchMoveItems || [];
+            if (app.moveDialogMode === 'batch' && multiSelect) {
+                const targetId = app.selectedTargetFolderId;
+                const items = app.batchMoveItems || [];
 
                 const fileIds = items.filter((i) => i.type === 'file').map((i) => i.id);
                 const folderIds = items.filter((i) => i.type === 'folder' && i.id !== targetId).map((i) => i.id);
 
-                const result = await window.fileOps.batchMove(fileIds, folderIds, targetId);
+                const result = await fileOps.batchMove(fileIds, folderIds, targetId);
 
                 this.closeMoveDialog();
-                window.multiSelect.clear();
-                window.loadFiles();
-                window.multiSelect.showBatchResult('move', result);
+                multiSelect.clear();
+                loadFiles();
+                multiSelect.showBatchResult('move', result);
 
                 return;
             }
 
-            if (window.app.moveDialogMode === 'file' && window.app.contextMenuTargetFile) {
-                const success = await window.fileOps.moveFile(window.app.contextMenuTargetFile.id, window.app.selectedTargetFolderId);
+            if (app.moveDialogMode === 'file' && app.contextMenuTargetFile) {
+                const success = await fileOps.moveFile(app.contextMenuTargetFile.id, app.selectedTargetFolderId);
                 if (success) {
                     this.closeMoveDialog();
                 }
-            } else if (window.app.moveDialogMode === 'folder' && window.app.contextMenuTargetFolder) {
-                const success = await window.fileOps.moveFolder(window.app.contextMenuTargetFolder.id, window.app.selectedTargetFolderId);
+            } else if (app.moveDialogMode === 'folder' && app.contextMenuTargetFolder) {
+                const success = await fileOps.moveFolder(app.contextMenuTargetFolder.id, app.selectedTargetFolderId);
                 if (success) {
                     this.closeMoveDialog();
                 }
@@ -363,13 +376,13 @@ const contextMenus = {
         const renameInput = document.getElementById('rename-input');
         const renameDialog = document.getElementById('rename-dialog');
 
-        window.app.renameMode = 'folder';
+        app.renameMode = 'folder';
         // Store the folder reference so it survives context menu cleanup
-        window.app.renameTarget = folder;
+        app.renameTarget = folder;
         renameInput.value = folder.name;
         // Update header text
         const headerSpan = renameDialog.querySelector('.rename-dialog-header span');
-        if (headerSpan) headerSpan.textContent = window.i18n ? window.i18n.t('dialogs.rename_folder') : 'Rename folder';
+        if (headerSpan) headerSpan.textContent = i18n ? i18n.t('dialogs.rename_folder') : 'Rename folder';
         renameDialog.style.display = 'flex';
         renameInput.focus();
         renameInput.select();
@@ -383,13 +396,13 @@ const contextMenus = {
         const renameInput = document.getElementById('rename-input');
         const renameDialog = document.getElementById('rename-dialog');
 
-        window.app.renameMode = 'file';
+        app.renameMode = 'file';
         // Store the file reference so it survives context menu cleanup
-        window.app.renameTarget = file;
+        app.renameTarget = file;
         renameInput.value = file.name;
         // Update header text
         const headerSpan = renameDialog.querySelector('.rename-dialog-header span');
-        if (headerSpan) headerSpan.textContent = window.i18n ? window.i18n.t('dialogs.rename_file') : 'Rename file';
+        if (headerSpan) headerSpan.textContent = i18n ? i18n.t('dialogs.rename_file') : 'Rename file';
         renameDialog.style.display = 'flex';
         renameInput.focus();
         renameInput.select();
@@ -400,8 +413,8 @@ const contextMenus = {
      */
     closeRenameDialog() {
         document.getElementById('rename-dialog').style.display = 'none';
-        window.app.contextMenuTargetFolder = null;
-        window.app.renameTarget = null;
+        app.contextMenuTargetFolder = null;
+        app.renameTarget = null;
     },
 
     /**
@@ -411,15 +424,15 @@ const contextMenus = {
      */
     async showMoveDialog(item, mode) {
         // Set mode
-        window.app.moveDialogMode = mode;
+        app.moveDialogMode = mode;
 
         // Reset selection
-        window.app.selectedTargetFolderId = '';
+        app.selectedTargetFolderId = '';
 
         // Ensure we have the home folder ID BEFORE calculating startFolderId
-        if (!window.app.userHomeFolderId) {
+        if (!app.userHomeFolderId) {
             console.log('[Move Dialog] Home folder ID not set, resolving...');
-            await window.resolveHomeFolder();
+            await resolveHomeFolder();
         }
 
         // Initialize dialog navigation state
@@ -437,44 +450,28 @@ const contextMenus = {
             startFolderId = item.parent_id;
         } else {
             // If item is at root level, start at user's home folder
-            startFolderId = window.app.userHomeFolderId || null;
+            startFolderId = app.userHomeFolderId || null;
         }
 
-        console.log(
-            '[Move Dialog] showMoveDialog - item:',
-            item,
-            'mode:',
-            mode,
-            'startFolderId:',
-            startFolderId,
-            'userHomeFolderId:',
-            window.app.userHomeFolderId
-        );
+        console.log('[Move Dialog] showMoveDialog - item:', item, 'mode:', mode, 'startFolderId:', startFolderId, 'userHomeFolderId:', app.userHomeFolderId);
 
         // Store the item being moved and navigation state
-        window.app.moveDialogItemId = item.id;
-        window.app.moveDialogItemMode = mode;
-        window.app.moveDialogCurrentFolderId = startFolderId;
+        app.moveDialogItemId = item.id;
+        app.moveDialogItemMode = mode;
+        app.moveDialogCurrentFolderId = startFolderId;
 
         // Build initial breadcrumb if starting at a non-home folder
         // This allows proper navigation back to home
         const breadcrumb = [];
-        if (startFolderId && startFolderId !== window.app.userHomeFolderId && startFolderName) {
+        if (startFolderId && startFolderId !== app.userHomeFolderId && startFolderName) {
             // We have the folder name, add it to breadcrumb
             breadcrumb.push({ id: startFolderId, name: startFolderName });
         }
-        window.app.moveDialogBreadcrumb = breadcrumb;
+        app.moveDialogBreadcrumb = breadcrumb;
 
         // Update dialog title (preserve icon)
         const dialogHeader = document.getElementById('move-file-dialog').querySelector('.rename-dialog-header');
-        const titleText =
-            mode === 'file'
-                ? window.i18n
-                    ? window.i18n.t('dialogs.move_file')
-                    : 'Move file'
-                : window.i18n
-                  ? window.i18n.t('dialogs.move_folder')
-                  : 'Move folder';
+        const titleText = mode === 'file' ? (i18n ? i18n.t('dialogs.move_file') : 'Move file') : i18n ? i18n.t('dialogs.move_folder') : 'Move folder';
         dialogHeader.innerHTML = `<i class="fas fa-arrows-alt dialog-header-icon"></i> <span>${titleText}</span>`;
 
         // Load folders for the starting location
@@ -489,8 +486,8 @@ const contextMenus = {
      */
     closeMoveDialog() {
         document.getElementById('move-file-dialog').style.display = 'none';
-        window.app.contextMenuTargetFile = null;
-        window.app.contextMenuTargetFolder = null;
+        app.contextMenuTargetFile = null;
+        app.contextMenuTargetFolder = null;
     },
 
     /**
@@ -499,28 +496,28 @@ const contextMenus = {
     async renameItem() {
         const newName = document.getElementById('rename-input').value.trim();
         if (!newName) {
-            alert(window.i18n ? window.i18n.t('errors.empty_name') : 'Name cannot be empty');
+            alert(i18n ? i18n.t('errors.empty_name') : 'Name cannot be empty');
             return;
         }
 
         // Use renameTarget which was saved before the context menu was closed
-        const target = window.app.renameTarget;
+        const target = app.renameTarget;
         if (!target) {
             console.error('No rename target available');
             return;
         }
 
-        if (window.app.renameMode === 'file') {
-            const success = await window.fileOps.renameFile(target.id, newName);
+        if (app.renameMode === 'file') {
+            const success = await fileOps.renameFile(target.id, newName);
             if (success) {
                 contextMenus.closeRenameDialog();
-                window.loadFiles();
+                loadFiles();
             }
-        } else if (window.app.renameMode === 'folder') {
-            const success = await window.fileOps.renameFolder(target.id, newName);
+        } else if (app.renameMode === 'folder') {
+            const success = await fileOps.renameFolder(target.id, newName);
             if (success) {
                 contextMenus.closeRenameDialog();
-                window.loadFiles();
+                loadFiles();
             }
         }
     },
@@ -538,12 +535,12 @@ const contextMenus = {
     async loadMoveDialogFolders(parentFolderId) {
         try {
             // Ensure we have the home folder ID before proceeding
-            if (!window.app.userHomeFolderId) {
-                await window.resolveHomeFolder();
+            if (!app.userHomeFolderId) {
+                await resolveHomeFolder();
             }
 
             // Get the effective folder ID
-            const effectiveParentId = parentFolderId || window.app.userHomeFolderId;
+            const effectiveParentId = parentFolderId || app.userHomeFolderId;
 
             // Must have a folder ID to proceed
             if (!effectiveParentId) {
@@ -576,9 +573,9 @@ const contextMenus = {
             folderSelectContainer.innerHTML = '';
 
             // Get current navigation state
-            const itemId = window.app.moveDialogItemId;
-            const mode = window.app.moveDialogItemMode;
-            const breadcrumb = window.app.moveDialogBreadcrumb || [];
+            const itemId = app.moveDialogItemId;
+            const mode = app.moveDialogItemMode;
+            const breadcrumb = app.moveDialogBreadcrumb || [];
 
             // Always show breadcrumb to allow navigation back to home
             this._renderMoveDialogBreadcrumb(breadcrumbContainer, breadcrumb, effectiveParentId);
@@ -590,42 +587,42 @@ const contextMenus = {
                 currentFolderOption.className = 'folder-select-item folder-select-current';
                 currentFolderOption.innerHTML = `
                     <i class="fas fa-check-circle check-icon"></i>
-                    <span>${window.i18n ? window.i18n.t('dialogs.select_this_folder') : 'Select this folder'}</span>
+                    <span>${i18n ? i18n.t('dialogs.select_this_folder') : 'Select this folder'}</span>
                 `;
                 currentFolderOption.addEventListener('click', () => {
                     document.querySelectorAll('.folder-select-item').forEach((item) => {
                         item.classList.remove('selected');
                     });
                     currentFolderOption.classList.add('selected');
-                    window.app.selectedTargetFolderId = effectiveParentId;
+                    app.selectedTargetFolderId = effectiveParentId;
                 });
                 folderSelectContainer.appendChild(currentFolderOption);
             }
 
             // Add "Go to parent" option if not at home folder
-            const isAtHomeFolder = effectiveParentId === window.app.userHomeFolderId;
+            const isAtHomeFolder = effectiveParentId === app.userHomeFolderId;
             if (!isAtHomeFolder || breadcrumb.length > 0) {
                 const parentOption = document.createElement('div');
                 parentOption.className = 'folder-select-item folder-navigate-up';
                 parentOption.innerHTML = `
                     <i class="fas fa-level-up-alt"></i>
-                    <span>${window.i18n ? window.i18n.t('dialogs.go_to_parent') : '.. (parent folder)'}</span>
+                    <span>${i18n ? i18n.t('dialogs.go_to_parent') : '.. (parent folder)'}</span>
                 `;
                 parentOption.addEventListener('click', () => {
                     // Navigate to parent folder
-                    const currentBreadcrumb = window.app.moveDialogBreadcrumb || [];
+                    const currentBreadcrumb = app.moveDialogBreadcrumb || [];
                     if (currentBreadcrumb.length > 0) {
                         // Remove current folder from breadcrumb
                         currentBreadcrumb.pop();
                         const parentFolder = currentBreadcrumb.length > 0 ? currentBreadcrumb[currentBreadcrumb.length - 1] : null;
-                        window.app.moveDialogBreadcrumb = currentBreadcrumb;
-                        window.app.moveDialogCurrentFolderId = parentFolder ? parentFolder.id : null;
+                        app.moveDialogBreadcrumb = currentBreadcrumb;
+                        app.moveDialogCurrentFolderId = parentFolder ? parentFolder.id : null;
                         this.loadMoveDialogFolders(parentFolder ? parentFolder.id : null);
                     } else {
                         // Go to root (home folder)
-                        window.app.moveDialogBreadcrumb = [];
-                        window.app.moveDialogCurrentFolderId = window.app.userHomeFolderId || null;
-                        this.loadMoveDialogFolders(window.app.userHomeFolderId || null);
+                        app.moveDialogBreadcrumb = [];
+                        app.moveDialogCurrentFolderId = app.userHomeFolderId || null;
+                        this.loadMoveDialogFolders(app.userHomeFolderId || null);
                     }
                 });
                 folderSelectContainer.appendChild(parentOption);
@@ -650,10 +647,10 @@ const contextMenus = {
                 // Click navigates INTO this folder
                 folderItem.addEventListener('click', () => {
                     // Add to breadcrumb
-                    const breadcrumb = window.app.moveDialogBreadcrumb || [];
+                    const breadcrumb = app.moveDialogBreadcrumb || [];
                     breadcrumb.push({ id: folder.id, name: folder.name });
-                    window.app.moveDialogBreadcrumb = breadcrumb;
-                    window.app.moveDialogCurrentFolderId = folder.id;
+                    app.moveDialogBreadcrumb = breadcrumb;
+                    app.moveDialogCurrentFolderId = folder.id;
                     this.loadMoveDialogFolders(folder.id);
                 });
 
@@ -667,30 +664,30 @@ const contextMenus = {
                 homeOption.className = 'folder-select-item folder-select-current';
                 homeOption.innerHTML = `
                     <i class="fas fa-check-circle check-icon"></i>
-                    <span>${window.i18n ? window.i18n.t('dialogs.move_to_home') : 'Move to Home folder'}</span>
+                    <span>${i18n ? i18n.t('dialogs.move_to_home') : 'Move to Home folder'}</span>
                 `;
                 homeOption.addEventListener('click', () => {
                     document.querySelectorAll('.folder-select-item').forEach((item) => {
                         item.classList.remove('selected');
                     });
                     homeOption.classList.add('selected');
-                    window.app.selectedTargetFolderId = ''; // Empty means root/home
+                    app.selectedTargetFolderId = ''; // Empty means root/home
                 });
                 folderSelectContainer.appendChild(homeOption);
             } else if (folders.length === 0) {
                 // Inside a subfolder with no children - show empty message
                 const emptyMsg = document.createElement('div');
                 emptyMsg.className = 'folder-select-empty';
-                emptyMsg.innerHTML = `<i class="fas fa-folder-open"></i> <span>${window.i18n ? window.i18n.t('dialogs.no_subfolders') : 'No subfolders to navigate'}</span>`;
+                emptyMsg.innerHTML = `<i class="fas fa-folder-open"></i> <span>${i18n ? i18n.t('dialogs.no_subfolders') : 'No subfolders to navigate'}</span>`;
                 folderSelectContainer.appendChild(emptyMsg);
             }
 
             // Set default selection to current folder
-            window.app.selectedTargetFolderId = parentFolderId || '';
+            app.selectedTargetFolderId = parentFolderId || '';
 
             // Translate new elements
-            if (window.i18n?.translateElement) {
-                window.i18n.translateElement(folderSelectContainer);
+            if (i18n?.translateElement) {
+                i18n.translateElement(folderSelectContainer);
             }
         } catch (error) {
             console.error('Error loading folders:', error);
@@ -704,16 +701,16 @@ const contextMenus = {
         if (!container) return;
         container.innerHTML = '';
 
-        const homeFolderId = window.app.userHomeFolderId;
-        const homeFolderName = window.app.userHomeFolderName || 'Home';
+        const homeFolderId = app.userHomeFolderId;
+        const homeFolderName = app.userHomeFolderName || 'Home';
 
         // Home icon (click to go to home folder)
         const homeItem = document.createElement('span');
         homeItem.className = 'move-breadcrumb-item';
         homeItem.innerHTML = '<i class="fas fa-home"></i>';
         homeItem.addEventListener('click', () => {
-            window.app.moveDialogBreadcrumb = [];
-            window.app.moveDialogCurrentFolderId = homeFolderId || null;
+            app.moveDialogBreadcrumb = [];
+            app.moveDialogCurrentFolderId = homeFolderId || null;
             this.loadMoveDialogFolders(homeFolderId || null);
         });
         container.appendChild(homeItem);
@@ -733,8 +730,8 @@ const contextMenus = {
             homeNameItem.textContent = homeFolderName;
             if (breadcrumb.length > 0) {
                 homeNameItem.addEventListener('click', () => {
-                    window.app.moveDialogBreadcrumb = [];
-                    window.app.moveDialogCurrentFolderId = homeFolderId || null;
+                    app.moveDialogBreadcrumb = [];
+                    app.moveDialogCurrentFolderId = homeFolderId || null;
                     this.loadMoveDialogFolders(homeFolderId || null);
                 });
             }
@@ -758,8 +755,8 @@ const contextMenus = {
             // Click to navigate back to this level
             if (index < breadcrumb.length - 1) {
                 item.addEventListener('click', () => {
-                    window.app.moveDialogBreadcrumb = breadcrumb.slice(0, index + 1);
-                    window.app.moveDialogCurrentFolderId = segment.id;
+                    app.moveDialogBreadcrumb = breadcrumb.slice(0, index + 1);
+                    app.moveDialogCurrentFolderId = segment.id;
                     this.loadMoveDialogFolders(segment.id);
                 });
             }
@@ -776,11 +773,11 @@ const contextMenus = {
     async loadAllFolders(_itemId, _mode) {
         // For batch mode, use the same navigation as regular move dialog
         // Initialize navigation state starting at home folder
-        window.app.moveDialogBreadcrumb = [];
-        window.app.moveDialogCurrentFolderId = window.app.userHomeFolderId || null;
+        app.moveDialogBreadcrumb = [];
+        app.moveDialogCurrentFolderId = app.userHomeFolderId || null;
 
         // Use loadMoveDialogFolders which uses /api/folders/{id}/contents
-        await this.loadMoveDialogFolders(window.app.userHomeFolderId || null);
+        await this.loadMoveDialogFolders(app.userHomeFolderId || null);
     },
 
     /**
@@ -793,7 +790,7 @@ const contextMenus = {
             const shareDialog = document.getElementById('share-dialog');
             if (!shareDialog) {
                 console.error('Share dialog element not found in DOM');
-                window.ui.showNotification('Error', 'Share dialog not available');
+                ui.showNotification('Error', 'Share dialog not available');
                 return;
             }
 
@@ -802,13 +799,7 @@ const contextMenus = {
             if (dialogHeader) {
                 const headerSpan = dialogHeader.querySelector('span');
                 const titleText =
-                    itemType === 'file'
-                        ? window.i18n
-                            ? window.i18n.t('dialogs.share_file')
-                            : 'Share file'
-                        : window.i18n
-                          ? window.i18n.t('dialogs.share_folder')
-                          : 'Share folder';
+                    itemType === 'file' ? (i18n ? i18n.t('dialogs.share_file') : 'Share file') : i18n ? i18n.t('dialogs.share_folder') : 'Share folder';
                 if (headerSpan) {
                     headerSpan.textContent = titleText;
                 } else {
@@ -832,11 +823,11 @@ const contextMenus = {
             if (permReshare) permReshare.checked = false;
 
             // Store the current item and type for use when creating the share
-            window.app.shareDialogItem = item;
-            window.app.shareDialogItemType = itemType;
+            app.shareDialogItem = item;
+            app.shareDialogItemType = itemType;
 
             // Check if item already has shares (async API call)
-            const existingShares = await window.fileSharing.getSharedLinksForItem(item.id, itemType);
+            const existingShares = await fileSharing.getSharedLinksForItem(item.id, itemType);
             const existingSharesContainer = document.getElementById('existing-shares-container');
 
             // Clear existing shares container
@@ -850,7 +841,7 @@ const contextMenus = {
                     const shareEl = document.createElement('div');
                     shareEl.className = 'existing-share-item';
 
-                    const expiresText = share.expires_at ? `Expires: ${window.fileSharing.formatExpirationDate(share.expires_at)}` : 'No expiration';
+                    const expiresText = share.expires_at ? `Expires: ${fileSharing.formatExpirationDate(share.expires_at)}` : 'No expiration';
 
                     // Share URL
                     const urlDiv = document.createElement('div');
@@ -899,7 +890,7 @@ const contextMenus = {
                     btn.addEventListener('click', (e) => {
                         e.preventDefault();
                         const url = btn.getAttribute('data-share-url');
-                        window.fileSharing.copyLinkToClipboard(url);
+                        fileSharing.copyLinkToClipboard(url);
                     });
                 });
 
@@ -909,12 +900,12 @@ const contextMenus = {
                         const shareId = btn.getAttribute('data-share-id');
 
                         showConfirmDialog({
-                            title: window.i18n ? window.i18n.t('dialogs.confirm_delete_share') : 'Delete link',
-                            message: window.i18n ? window.i18n.t('dialogs.confirm_delete_share_msg') : 'Are you sure you want to delete this shared link?',
-                            confirmText: window.i18n ? window.i18n.t('actions.delete') : 'Delete'
+                            title: i18n ? i18n.t('dialogs.confirm_delete_share') : 'Delete link',
+                            message: i18n ? i18n.t('dialogs.confirm_delete_share_msg') : 'Are you sure you want to delete this shared link?',
+                            confirmText: i18n ? i18n.t('actions.delete') : 'Delete'
                         }).then(async (confirmed) => {
                             if (confirmed) {
-                                await window.fileSharing.removeSharedLink(shareId);
+                                await fileSharing.removeSharedLink(shareId);
                                 btn.closest('.existing-share-item').remove();
                                 if (existingSharesContainer.children.length === 0) {
                                     document.getElementById('existing-shares-section').classList.add('hidden');
@@ -936,7 +927,7 @@ const contextMenus = {
             console.log('Share dialog opened for', itemType, item.name);
         } catch (error) {
             console.error('Error opening share dialog:', error);
-            window.ui.showNotification('Error', 'Could not open share dialog');
+            ui.showNotification('Error', 'Could not open share dialog');
         }
     },
 
@@ -944,8 +935,8 @@ const contextMenus = {
      * Create a shared link with the configured options
      */
     async createSharedLink() {
-        if (!window.app.shareDialogItem || !window.app.shareDialogItemType) {
-            window.ui.showNotification('Error', 'Could not share the item');
+        if (!app.shareDialogItem || !app.shareDialogItemType) {
+            ui.showNotification('Error', 'Could not share the item');
             return;
         }
 
@@ -956,8 +947,8 @@ const contextMenus = {
         const permissionWrite = document.getElementById('share-permission-write').checked;
         const permissionReshare = document.getElementById('share-permission-reshare').checked;
 
-        const item = window.app.shareDialogItem;
-        const itemType = window.app.shareDialogItemType;
+        const item = app.shareDialogItem;
+        const itemType = app.shareDialogItemType;
 
         // Build DTO for backend API
         const createDto = {
@@ -1002,13 +993,13 @@ const contextMenus = {
             }
 
             // Show success message
-            window.ui.showNotification(
-                window.i18n ? window.i18n.t('notifications.link_created') : 'Link created',
-                window.i18n ? window.i18n.t('notifications.share_success') : 'Shared link created successfully'
+            ui.showNotification(
+                i18n ? i18n.t('notifications.link_created') : 'Link created',
+                i18n ? i18n.t('notifications.share_success') : 'Shared link created successfully'
             );
         } catch (error) {
             console.error('Error creating shared link:', error);
-            window.ui.showNotification('Error', error.message || 'Could not create shared link');
+            ui.showNotification('Error', error.message || 'Could not create shared link');
         }
     },
 
@@ -1023,7 +1014,7 @@ const contextMenus = {
         document.getElementById('notification-message').value = '';
 
         // Store the URL for later use
-        window.app.notificationShareUrl = shareUrl;
+        app.notificationShareUrl = shareUrl;
 
         // Show dialog
         document.getElementById('notification-dialog').style.display = 'flex';
@@ -1035,26 +1026,26 @@ const contextMenus = {
     sendShareNotification() {
         const email = document.getElementById('notification-email').value.trim();
         const message = document.getElementById('notification-message').value.trim();
-        const shareUrl = window.app.notificationShareUrl;
+        const shareUrl = app.notificationShareUrl;
 
         if (!email || !shareUrl) {
-            window.ui.showNotification('Error', 'Please enter a valid email address');
+            ui.showNotification('Error', 'Please enter a valid email address');
             return;
         }
 
         // Validate email format
         const emailRegex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;
         if (!emailRegex.test(email)) {
-            window.ui.showNotification('Error', 'Please enter a valid email address');
+            ui.showNotification('Error', 'Please enter a valid email address');
             return;
         }
 
         try {
-            window.fileSharing.sendShareNotification(shareUrl, email, message);
+            fileSharing.sendShareNotification(shareUrl, email, message);
             document.getElementById('notification-dialog').style.display = 'none';
         } catch (error) {
             console.error('Error sending notification:', error);
-            window.ui.showNotification('Error', 'Could not send notification');
+            ui.showNotification('Error', 'Could not send notification');
         }
     },
 
@@ -1064,8 +1055,8 @@ const contextMenus = {
     closeShareDialog() {
         const dialog = document.getElementById('share-dialog');
         if (dialog) dialog.style.display = 'none';
-        window.app.shareDialogItem = null;
-        window.app.shareDialogItemType = null;
+        app.shareDialogItem = null;
+        app.shareDialogItemType = null;
     },
 
     /**
@@ -1073,7 +1064,7 @@ const contextMenus = {
      */
     closeNotificationDialog() {
         document.getElementById('notification-dialog').style.display = 'none';
-        window.app.notificationShareUrl = null;
+        app.notificationShareUrl = null;
     },
 
     _selectedPlaylistId: null,
@@ -1089,11 +1080,11 @@ const contextMenus = {
         }
 
         // Store the file(s) to add
-        window.app.playlistDialogFiles = [file];
+        app.playlistDialogFiles = [file];
 
         // Update files info
         if (filesInfo) {
-            filesInfo.innerHTML = `<strong>${window.i18n ? window.i18n.t('music.selected_files', 'Selected:') : 'Selected:'} </strong>${file.name}`;
+            filesInfo.innerHTML = `<strong>${i18n ? i18n.t('music.selected_files', 'Selected:') : 'Selected:'} </strong>${file.name}`;
         }
 
         // Reset selection
@@ -1117,12 +1108,12 @@ const contextMenus = {
             this._renderPlaylistSelect(container, playlists);
         } catch (err) {
             console.error('Error loading playlists:', err);
-            container.innerHTML = `<div class="folder-select-empty">${window.i18n ? window.i18n.t('music.load_error', 'Error loading playlists') : 'Error loading playlists'}</div>`;
+            container.innerHTML = `<div class="folder-select-empty">${i18n ? i18n.t('music.load_error', 'Error loading playlists') : 'Error loading playlists'}</div>`;
         }
     },
 
     _renderPlaylistSelect(container, playlists) {
-        const t = (key, fallback) => (window.i18n ? window.i18n.t(key, fallback) : fallback);
+        const t = (key, fallback) => (i18n ? i18n.t(key, fallback) : fallback);
 
         container.innerHTML = '';
 
@@ -1157,7 +1148,7 @@ const contextMenus = {
 
     async addSelectedFilesToPlaylist() {
         const playlistId = this._selectedPlaylistId;
-        const files = window.app.playlistDialogFiles || [];
+        const files = app.playlistDialogFiles || [];
 
         if (!playlistId || files.length === 0) return;
 
@@ -1181,23 +1172,20 @@ const contextMenus = {
             }
 
             await resp.json();
-            window.ui.showNotification(
-                window.i18n ? window.i18n.t('music.added', 'Added!') : 'Added!',
-                `${files.length} ${files.length === 1 ? 'track' : 'tracks'} ${window.i18n ? window.i18n.t('music.added_to_playlist', 'added to playlist') : 'added to playlist'}`
+            ui.showNotification(
+                i18n ? i18n.t('music.added', 'Added!') : 'Added!',
+                `${files.length} ${files.length === 1 ? 'track' : 'tracks'} ${i18n ? i18n.t('music.added_to_playlist', 'added to playlist') : 'added to playlist'}`
             );
 
             this.closePlaylistDialog();
 
             // Refresh music view if open
-            if (window.musicView?.playlists) {
-                window.musicView._loadPlaylists();
+            if (musicView?.playlists) {
+                musicView._loadPlaylists();
             }
         } catch (err) {
             console.error('Error adding to playlist:', err);
-            window.ui.showNotification(
-                window.i18n ? window.i18n.t('music.error', 'Error') : 'Error',
-                err.message || window.i18n.t('music.add_error', 'Could not add tracks to playlist')
-            );
+            ui.showNotification(i18n ? i18n.t('music.error', 'Error') : 'Error', err.message || i18n.t('music.add_error', 'Could not add tracks to playlist'));
             if (addBtn) addBtn.disabled = false;
         }
     },
@@ -1210,7 +1198,7 @@ const contextMenus = {
                 dialog.style.display = 'none';
             }, 200);
         }
-        window.app.playlistDialogFiles = null;
+        app.playlistDialogFiles = null;
         this._selectedPlaylistId = null;
     },
 
@@ -1220,5 +1208,4 @@ const contextMenus = {
     }
 };
 
-// Expose context menus module globally
-window.contextMenus = contextMenus;
+export { contextMenus };
diff --git a/static/js/features/files/fileOperations.js b/static/js/features/files/fileOperations.js
index aef21479..868d73f3 100644
--- a/static/js/features/files/fileOperations.js
+++ b/static/js/features/files/fileOperations.js
@@ -3,6 +3,14 @@
  * This file handles file and folder operations (create, move, delete, rename, upload)
  */
 
+import { refreshUserData } from '../../app/authSession.js';
+import { loadFiles } from '../../app/filesView.js';
+import { app } from '../../app/state.js';
+import { showConfirmDialog, ui } from '../../app/ui.js';
+import { getCsrfHeaders, getCsrfToken } from '../../core/csrf.js';
+import { i18n } from '../../core/i18n.js';
+import { notifications } from '../../core/notifications.js';
+
 /**
  * Get authorization headers for API requests.
  * Tokens are now in HttpOnly cookies — no explicit Authorization header needed.
@@ -22,13 +30,13 @@ const fileOps = {
 
     /** Start a new upload batch in the notification bell */
     _initUploadToast(totalFiles, folderName) {
-        this._currentBatchId = window.notifications ? window.notifications.addUploadBatch(totalFiles, folderName) : null;
+        this._currentBatchId = notifications ? notifications.addUploadBatch(totalFiles, folderName) : null;
     },
 
     /** Finalise the batch in the notification bell */
     _finishUploadToast(successCount, totalFiles) {
-        if (window.notifications && this._currentBatchId) {
-            window.notifications.finishBatch(this._currentBatchId, successCount, totalFiles);
+        if (notifications && this._currentBatchId) {
+            notifications.finishBatch(this._currentBatchId, successCount, totalFiles);
         }
     },
 
@@ -58,7 +66,7 @@ const fileOps = {
     _uploadFileXHR(formData, batchId, fileName, timeoutMs = 120000) {
         return new Promise((resolve) => {
             const xhr = new XMLHttpRequest();
-            const notif = window.notifications;
+            const notif = notifications;
             // Do NOT set xhr.timeout — it is a TOTAL deadline from send() to
             // response and would kill large uploads even while data is flowing.
             // Instead we rely on the stall timer (no progress for N seconds)
@@ -299,13 +307,13 @@ const fileOps = {
 
             const totalFiles = readableFiles.length;
 
-            if (skippedEntries.length > 0 && window.notifications) {
-                const locale = window.i18n?.getCurrentLocale?.() || 'en';
+            if (skippedEntries.length > 0 && notifications) {
+                const locale = i18n?.getCurrentLocale?.() || 'en';
                 const title = locale.startsWith('es') ? 'Entradas omitidas' : 'Entries skipped';
                 const text = locale.startsWith('es')
                     ? `Se omitieron ${skippedEntries.length} carpeta(s)/entrada(s) no legibles. Usa "Subir carpeta".`
                     : `${skippedEntries.length} unreadable folder/entry items were skipped. Use "Upload folder".`;
-                window.notifications.addNotification({
+                notifications.addNotification({
                     icon: 'fa-folder-open',
                     iconClass: 'upload',
                     title,
@@ -331,7 +339,7 @@ const fileOps = {
 
                 const formData = new FormData();
 
-                const targetFolderId = window.app.currentPath || window.app.userHomeFolderId;
+                const targetFolderId = app.currentPath || app.userHomeFolderId;
                 if (targetFolderId) formData.append('folder_id', targetFolderId);
                 formData.append('file', file);
 
@@ -353,9 +361,9 @@ const fileOps = {
                     progressBar.style.width = `${(uploadedCount / totalFiles) * 100}%`;
                 }
                 // Notify bell of per-file completion
-                if (window.notifications && batchId) {
+                if (notifications && batchId) {
                     try {
-                        window.notifications.fileCompleted(batchId, result.ok);
+                        notifications.fileCompleted(batchId, result.ok);
                     } catch (e) {
                         console.warn('Batch progress update failed:', e);
                     }
@@ -366,8 +374,8 @@ const fileOps = {
                     console.log(`Successfully uploaded ${file.name}`, result.data);
                 } else {
                     console.error(`Upload error for ${file.name}`);
-                    if (result.isTimeout && window.notifications) {
-                        window.notifications.addNotification({
+                    if (result.isTimeout && notifications) {
+                        notifications.addNotification({
                             icon: 'fa-clock',
                             iconClass: 'error',
                             title: file.name,
@@ -375,9 +383,9 @@ const fileOps = {
                         });
                     }
                     if (result.isQuotaError) {
-                        const msg = result.errorMsg || window.i18n?.t('storage_quota_exceeded') || 'Storage quota exceeded';
-                        if (window.notifications) {
-                            window.notifications.addNotification({
+                        const msg = result.errorMsg || i18n?.t('storage_quota_exceeded') || 'Storage quota exceeded';
+                        if (notifications) {
+                            notifications.addNotification({
                                 icon: 'fa-exclamation-triangle',
                                 iconClass: 'error',
                                 title: file.name,
@@ -393,14 +401,12 @@ const fileOps = {
             this._finishUploadToast(successCount, totalFiles);
 
             // Refresh storage usage display
-            if (typeof window.refreshUserData === 'function') {
-                try {
-                    await window.refreshUserData();
-                } catch (_) {}
-            }
+            try {
+                await refreshUserData();
+            } catch (_) {}
 
             try {
-                await window.loadFiles({ forceRefresh: true });
+                await loadFiles({ forceRefresh: true });
             } catch (reloadError) {
                 console.error('Error reloading files:', reloadError);
             }
@@ -466,7 +472,7 @@ const fileOps = {
                 return;
             }
 
-            const currentFolderId = window.app.currentPath || window.app.userHomeFolderId;
+            const currentFolderId = app.currentPath || app.userHomeFolderId;
 
             // Build folder structure from relative paths
             const folderMap = new Map();
@@ -528,7 +534,7 @@ const fileOps = {
                         .filter(Boolean)
                 )
             ];
-            const locale = window.i18n?.getCurrentLocale?.() || 'en';
+            const locale = i18n?.getCurrentLocale?.() || 'en';
             const rootFolderLabel =
                 rootFolderNames.length <= 1
                     ? rootFolderNames[0] || ''
@@ -585,9 +591,9 @@ const fileOps = {
                             console.warn(`[SKIP] #${idx} ${rel} — cannot read 0-byte file (FIFO/pipe?), skipping`);
                             uploadedCount++;
                             successCount++;
-                            if (window.notifications && batchId) {
+                            if (notifications && batchId) {
                                 try {
-                                    window.notifications.fileCompleted(batchId, true);
+                                    notifications.fileCompleted(batchId, true);
                                 } catch (_) {}
                             }
                             return;
@@ -617,9 +623,9 @@ const fileOps = {
 
                 uploadedCount++;
 
-                if (window.notifications && batchId) {
+                if (notifications && batchId) {
                     try {
-                        window.notifications.fileCompleted(batchId, result.ok);
+                        notifications.fileCompleted(batchId, result.ok);
                     } catch (_) {}
                 }
                 if (progressBar && uploadedCount % 10 === 0) {
@@ -633,8 +639,8 @@ const fileOps = {
                     successCount++;
                 } else if (result.isQuotaError) {
                     quotaStop = true;
-                    if (window.notifications) {
-                        window.notifications.addNotification({
+                    if (notifications) {
+                        notifications.addNotification({
                             icon: 'fa-exclamation-triangle',
                             iconClass: 'error',
                             title: file.name,
@@ -661,14 +667,12 @@ const fileOps = {
 
             this._finishUploadToast(successCount, totalFiles);
 
-            if (typeof window.refreshUserData === 'function') {
-                try {
-                    await window.refreshUserData();
-                } catch (_) {}
-            }
+            try {
+                await refreshUserData();
+            } catch (_) {}
 
             try {
-                await window.loadFiles({ forceRefresh: true });
+                await loadFiles({ forceRefresh: true });
             } catch (reloadError) {
                 console.error('Error reloading files:', reloadError);
             }
@@ -699,7 +703,7 @@ const fileOps = {
                 },
                 body: JSON.stringify({
                     name: name,
-                    parent_id: window.app.currentPath || window.app.userHomeFolderId || null
+                    parent_id: app.currentPath || app.userHomeFolderId || null
                 })
             });
 
@@ -710,17 +714,17 @@ const fileOps = {
 
                 // Optimistic UI: add folder card directly from server response
                 // — no reload needed since the backend already confirmed creation.
-                window.ui.addFolderToView(folder);
+                ui.addFolderToView(folder);
 
-                window.ui.showNotification('Folder created', `"${name}" created successfully`);
+                ui.showNotification('Folder created', `"${name}" created successfully`);
             } else {
                 const errorData = await response.text();
                 console.error('Create folder error:', errorData);
-                window.ui.showNotification('Error', 'Error creating the folder');
+                ui.showNotification('Error', 'Error creating the folder');
             }
         } catch (error) {
             console.error('Error creating folder:', error);
-            window.ui.showNotification('Error', 'Error creating the folder');
+            ui.showNotification('Error', 'Error creating the folder');
         }
     },
 
@@ -745,8 +749,8 @@ const fileOps = {
 
             if (response.ok) {
                 // Reload files after moving
-                await window.loadFiles();
-                window.ui.showNotification('File moved', 'File moved successfully');
+                await loadFiles();
+                ui.showNotification('File moved', 'File moved successfully');
                 return true;
             } else {
                 let errorMessage = 'Unknown error';
@@ -756,12 +760,12 @@ const fileOps = {
                 } catch (_e) {
                     errorMessage = 'Error processing server response';
                 }
-                window.ui.showNotification('Error', `Error moving the file: ${errorMessage}`);
+                ui.showNotification('Error', `Error moving the file: ${errorMessage}`);
                 return false;
             }
         } catch (error) {
             console.error('Error moving file:', error);
-            window.ui.showNotification('Error', 'Error moving the file');
+            ui.showNotification('Error', 'Error moving the file');
             return false;
         }
     },
@@ -787,8 +791,8 @@ const fileOps = {
 
             if (response.ok) {
                 // Reload files after moving
-                await window.loadFiles();
-                window.ui.showNotification('Folder moved', 'Folder moved successfully');
+                await loadFiles();
+                ui.showNotification('Folder moved', 'Folder moved successfully');
                 return true;
             } else {
                 let errorMessage = 'Unknown error';
@@ -798,12 +802,12 @@ const fileOps = {
                 } catch (_e) {
                     errorMessage = 'Error processing server response';
                 }
-                window.ui.showNotification('Error', `Error moving the folder: ${errorMessage}`);
+                ui.showNotification('Error', `Error moving the folder: ${errorMessage}`);
                 return false;
             }
         } catch (error) {
             console.error('Error moving folder:', error);
-            window.ui.showNotification('Error', 'Error moving the folder');
+            ui.showNotification('Error', 'Error moving the folder');
             return false;
         }
     },
@@ -890,8 +894,8 @@ const fileOps = {
             if (response.ok) {
                 await response.json();
                 // Reload files after copying
-                await window.loadFiles();
-                window.ui.showNotification('File copied', 'File copied successfully');
+                await loadFiles();
+                ui.showNotification('File copied', 'File copied successfully');
                 return true;
             } else {
                 let errorMessage = 'Unknown error';
@@ -901,12 +905,12 @@ const fileOps = {
                 } catch (_e) {
                     errorMessage = 'Error processing server response';
                 }
-                window.ui.showNotification('Error', `Error copying the file: ${errorMessage}`);
+                ui.showNotification('Error', `Error copying the file: ${errorMessage}`);
                 return false;
             }
         } catch (error) {
             console.error('Error copying file:', error);
-            window.ui.showNotification('Error', 'Error copying the file');
+            ui.showNotification('Error', 'Error copying the file');
             return false;
         }
     },
@@ -920,7 +924,7 @@ const fileOps = {
      */
     async copyFolder(_folderId, _targetFolderId) {
         // Folder copy is not yet implemented in the backend
-        window.ui.showNotification('Not implemented', 'Folder copy is not yet supported');
+        ui.showNotification('Not implemented', 'Folder copy is not yet supported');
         return false;
     },
 
@@ -954,7 +958,7 @@ const fileOps = {
 
             // Note: Folder copy is not yet implemented in batch API
             if (folderIds.length > 0) {
-                window.ui.showNotification('Info', 'Folder copy is not yet supported in batch mode');
+                ui.showNotification('Info', 'Folder copy is not yet supported in batch mode');
                 errors += folderIds.lenngth;
             }
         } catch (err) {
@@ -990,9 +994,9 @@ const fileOps = {
             console.log('Response status:', response.status);
 
             if (response.ok) {
-                window.ui.showNotification(
-                    window.i18n ? window.i18n.t('notifications.file_renamed') : 'File renamed',
-                    window.i18n ? window.i18n.t('notifications.file_renamed_to', { name: newName }) : `File renamed to "${newName}"`
+                ui.showNotification(
+                    i18n ? i18n.t('notifications.file_renamed') : 'File renamed',
+                    i18n ? i18n.t('notifications.file_renamed_to', { name: newName }) : `File renamed to "${newName}"`
                 );
                 return true;
             } else {
@@ -1005,12 +1009,12 @@ const fileOps = {
                 } catch (_e) {
                     errorMessage = errorText || response.statusText;
                 }
-                window.ui.showNotification('Error', `Error renaming the file: ${errorMessage}`);
+                ui.showNotification('Error', `Error renaming the file: ${errorMessage}`);
                 return false;
             }
         } catch (error) {
             console.error('Error renaming file:', error);
-            window.ui.showNotification('Error', 'Error renaming the file');
+            ui.showNotification('Error', 'Error renaming the file');
             return false;
         }
     },
@@ -1037,7 +1041,7 @@ const fileOps = {
             console.log('Response status:', response.status);
 
             if (response.ok) {
-                window.ui.showNotification('Folder renamed', `Folder renamed to "${newName}"`);
+                ui.showNotification('Folder renamed', `Folder renamed to "${newName}"`);
                 return true;
             } else {
                 const errorText = await response.text();
@@ -1053,12 +1057,12 @@ const fileOps = {
                     errorMessage = errorText || response.statusText;
                 }
 
-                window.ui.showNotification('Error', `Error renaming the folder: ${errorMessage}`);
+                ui.showNotification('Error', `Error renaming the folder: ${errorMessage}`);
                 return false;
             }
         } catch (error) {
             console.error('Error renaming folder:', error);
-            window.ui.showNotification('Error', 'Error renaming the folder');
+            ui.showNotification('Error', 'Error renaming the folder');
             return false;
         }
     },
@@ -1071,11 +1075,9 @@ const fileOps = {
      */
     async deleteFile(fileId, fileName) {
         const confirmed = await showConfirmDialog({
-            title: window.i18n ? window.i18n.t('dialogs.confirm_delete') : 'Move to trash',
-            message: window.i18n
-                ? window.i18n.t('dialogs.confirm_delete_file', { name: fileName })
-                : `Are you sure you want to move the file "${fileName}" to trash?`,
-            confirmText: window.i18n ? window.i18n.t('actions.delete') : 'Delete'
+            title: i18n ? i18n.t('dialogs.confirm_delete') : 'Move to trash',
+            message: i18n ? i18n.t('dialogs.confirm_delete_file', { name: fileName }) : `Are you sure you want to move the file "${fileName}" to trash?`,
+            confirmText: i18n ? i18n.t('actions.delete') : 'Delete'
         });
         if (!confirmed) return false;
 
@@ -1087,8 +1089,8 @@ const fileOps = {
             });
 
             if (response.ok) {
-                window.loadFiles();
-                window.ui.showNotification('File moved to trash', `"${fileName}" moved to trash`);
+                loadFiles();
+                ui.showNotification('File moved to trash', `"${fileName}" moved to trash`);
                 return true;
             } else {
                 // Fallback to direct deletion if trash fails
@@ -1098,17 +1100,17 @@ const fileOps = {
                 });
 
                 if (fallbackResponse.ok) {
-                    window.loadFiles();
-                    window.ui.showNotification('File deleted', `"${fileName}" deleted successfully`);
+                    loadFiles();
+                    ui.showNotification('File deleted', `"${fileName}" deleted successfully`);
                     return true;
                 } else {
-                    window.ui.showNotification('Error', 'Error deleting the file');
+                    ui.showNotification('Error', 'Error deleting the file');
                     return false;
                 }
             }
         } catch (error) {
             console.error('Error deleting file:', error);
-            window.ui.showNotification('Error', 'Error deleting the file');
+            ui.showNotification('Error', 'Error deleting the file');
             return false;
         }
     },
@@ -1121,11 +1123,11 @@ const fileOps = {
      */
     async deleteFolder(folderId, folderName) {
         const confirmed = await showConfirmDialog({
-            title: window.i18n ? window.i18n.t('dialogs.confirm_delete') : 'Move to trash',
-            message: window.i18n
-                ? window.i18n.t('dialogs.confirm_delete_folder', { name: folderName })
+            title: i18n ? i18n.t('dialogs.confirm_delete') : 'Move to trash',
+            message: i18n
+                ? i18n.t('dialogs.confirm_delete_folder', { name: folderName })
                 : `Are you sure you want to move the folder "${folderName}" and all its contents to trash?`,
-            confirmText: window.i18n ? window.i18n.t('actions.delete') : 'Delete'
+            confirmText: i18n ? i18n.t('actions.delete') : 'Delete'
         });
         if (!confirmed) return false;
 
@@ -1138,12 +1140,12 @@ const fileOps = {
 
             if (response.ok) {
                 // If we're inside the folder we just deleted, go back up
-                if (window.app.currentPath === folderId) {
-                    window.app.currentPath = '';
-                    window.ui.updateBreadcrumb('');
+                if (app.currentPath === folderId) {
+                    app.currentPath = '';
+                    ui.updateBreadcrumb('');
                 }
-                window.loadFiles();
-                window.ui.showNotification('Folder moved to trash', `"${folderName}" moved to trash`);
+                loadFiles();
+                ui.showNotification('Folder moved to trash', `"${folderName}" moved to trash`);
                 return true;
             } else {
                 // Fallback to direct deletion if trash fails
@@ -1154,21 +1156,21 @@ const fileOps = {
 
                 if (fallbackResponse.ok) {
                     // If we're inside the folder we just deleted, go back up
-                    if (window.app.currentPath === folderId) {
-                        window.app.currentPath = '';
-                        window.ui.updateBreadcrumb('');
+                    if (app.currentPath === folderId) {
+                        app.currentPath = '';
+                        ui.updateBreadcrumb('');
                     }
-                    window.loadFiles();
-                    window.ui.showNotification('Folder deleted', `"${folderName}" deleted successfully`);
+                    loadFiles();
+                    ui.showNotification('Folder deleted', `"${folderName}" deleted successfully`);
                     return true;
                 } else {
-                    window.ui.showNotification('Error', 'Error deleting the folder');
+                    ui.showNotification('Error', 'Error deleting the folder');
                     return false;
                 }
             }
         } catch (error) {
             console.error('Error deleting folder:', error);
-            window.ui.showNotification('Error', 'Error deleting the folder');
+            ui.showNotification('Error', 'Error deleting the folder');
             return false;
         }
     },
@@ -1212,15 +1214,15 @@ const fileOps = {
             });
 
             if (response.ok) {
-                window.ui.showNotification('Item restored', 'Item restored successfully');
+                ui.showNotification('Item restored', 'Item restored successfully');
                 return true;
             } else {
-                window.ui.showNotification('Error', 'Error restoring the item');
+                ui.showNotification('Error', 'Error restoring the item');
                 return false;
             }
         } catch (error) {
             console.error('Error restoring item from trash:', error);
-            window.ui.showNotification('Error', 'Error restoring the item');
+            ui.showNotification('Error', 'Error restoring the item');
             return false;
         }
     },
@@ -1232,11 +1234,11 @@ const fileOps = {
      */
     async deletePermanently(trashId) {
         const confirmed = await showConfirmDialog({
-            title: window.i18n ? window.i18n.t('dialogs.confirm_permanent_delete') : 'Delete permanently',
-            message: window.i18n
-                ? window.i18n.t('dialogs.confirm_permanent_delete_msg')
+            title: i18n ? i18n.t('dialogs.confirm_permanent_delete') : 'Delete permanently',
+            message: i18n
+                ? i18n.t('dialogs.confirm_permanent_delete_msg')
                 : 'Are you sure you want to permanently delete this item? This action cannot be undone.',
-            confirmText: window.i18n ? window.i18n.t('actions.delete_permanently') : 'Delete permanently'
+            confirmText: i18n ? i18n.t('actions.delete_permanently') : 'Delete permanently'
         });
         if (!confirmed) return false;
 
@@ -1247,15 +1249,15 @@ const fileOps = {
             });
 
             if (response.ok) {
-                window.ui.showNotification('Item deleted', 'Item permanently deleted');
+                ui.showNotification('Item deleted', 'Item permanently deleted');
                 return true;
             } else {
-                window.ui.showNotification('Error', 'Error deleting the item');
+                ui.showNotification('Error', 'Error deleting the item');
                 return false;
             }
         } catch (error) {
             console.error('Error deleting item permanently:', error);
-            window.ui.showNotification('Error', 'Error deleting the item');
+            ui.showNotification('Error', 'Error deleting the item');
             return false;
         }
     },
@@ -1266,11 +1268,9 @@ const fileOps = {
      */
     async emptyTrash() {
         const confirmed = await showConfirmDialog({
-            title: window.i18n ? window.i18n.t('dialogs.confirm_empty_trash') : 'Empty trash',
-            message: window.i18n
-                ? window.i18n.t('trash.empty_confirm')
-                : 'Are you sure you want to empty the trash? This action will permanently delete all items.',
-            confirmText: window.i18n ? window.i18n.t('actions.empty_trash') : 'Empty trash'
+            title: i18n ? i18n.t('dialogs.confirm_empty_trash') : 'Empty trash',
+            message: i18n ? i18n.t('trash.empty_confirm') : 'Are you sure you want to empty the trash? This action will permanently delete all items.',
+            confirmText: i18n ? i18n.t('actions.empty_trash') : 'Empty trash'
         });
         if (!confirmed) return false;
 
@@ -1281,15 +1281,15 @@ const fileOps = {
             });
 
             if (response.ok) {
-                window.ui.showNotification('Trash emptied', 'The trash has been emptied successfully');
+                ui.showNotification('Trash emptied', 'The trash has been emptied successfully');
                 return true;
             } else {
-                window.ui.showNotification('Error', 'Error emptying the trash');
+                ui.showNotification('Error', 'Error emptying the trash');
                 return false;
             }
         } catch (error) {
             console.error('Error emptying trash:', error);
-            window.ui.showNotification('Error', 'Error emptying the trash');
+            ui.showNotification('Error', 'Error emptying the trash');
             return false;
         }
     },
@@ -1315,11 +1315,11 @@ const fileOps = {
                 document.body.removeChild(link);
                 URL.revokeObjectURL(url);
             } else {
-                window.ui.showNotification('Error', 'Error downloading the file');
+                ui.showNotification('Error', 'Error downloading the file');
             }
         } catch (error) {
             console.error('Error downloading file:', error);
-            window.ui.showNotification('Error', 'Error downloading the file');
+            ui.showNotification('Error', 'Error downloading the file');
         }
     },
 
@@ -1331,7 +1331,7 @@ const fileOps = {
     async downloadFolder(folderId, folderName) {
         try {
             // Show notification to user
-            window.ui.showNotification('Preparing download', 'Preparing the folder for download...');
+            ui.showNotification('Preparing download', 'Preparing the folder for download...');
 
             const response = await fetch(`/api/folders/${folderId}/download?format=zip`, {
                 headers: getAuthHeaders()
@@ -1347,14 +1347,13 @@ const fileOps = {
                 document.body.removeChild(link);
                 URL.revokeObjectURL(url);
             } else {
-                window.ui.showNotification('Error', 'Error downloading the folder');
+                ui.showNotification('Error', 'Error downloading the folder');
             }
         } catch (error) {
             console.error('Error downloading folder:', error);
-            window.ui.showNotification('Error', 'Error downloading the folder');
+            ui.showNotification('Error', 'Error downloading the folder');
         }
     }
 };
 
-// Expose file operations module globally
-window.fileOps = fileOps;
+export { fileOps, getAuthHeaders };
diff --git a/static/js/features/files/inlineViewer.js b/static/js/features/files/inlineViewer.js
index e1ce5fb8..1f44e9fe 100644
--- a/static/js/features/files/inlineViewer.js
+++ b/static/js/features/files/inlineViewer.js
@@ -3,6 +3,11 @@
  * A simpler approach to viewing files that doesn't rely on complex DOM manipulation
  */
 
+import { updateHistory } from '../../app/main.js';
+import { app } from '../../app/state.js';
+import { isTextViewable } from '../../core/formatters.js';
+import { wopiEditor } from './wopiEditor.js';
+
 class InlineViewer {
     constructor() {
         this.setupViewer();
@@ -97,9 +102,9 @@ class InlineViewer {
         const ext = (file.name || '').split('.').pop().toLowerCase();
         const imageExts = ['jpg', 'jpeg', 'png', 'gif', 'svg', 'webp', 'bmp', 'ico', 'heic', 'heif', 'avif', 'tiff'];
         const isImage = file.mime_type?.startsWith('image/') || imageExts.includes(ext);
-        if (!isImage && window.wopiEditor && (await window.wopiEditor.canEdit(file.name))) {
+        if (!isImage && wopiEditor && (await wopiEditor.canEdit(file.name))) {
             try {
-                window.wopiEditor.openInModal(file.id, file.name, 'edit');
+                wopiEditor.openInModal(file.id, file.name, 'edit');
                 return;
             } catch (e) {
                 console.warn('WOPI editor failed, falling back to inline viewer:', e);
@@ -204,9 +209,9 @@ class InlineViewer {
         modal.classList.add('active');
     }
 
-    // Check if a MIME type is text-viewable — delegates to window.isTextViewable
+    // Check if a MIME type is text-viewable
     isTextViewable(mimeType) {
-        return window.isTextViewable ? window.isTextViewable(mimeType) : false;
+        return isTextViewable(mimeType);
     }
 
     // Creates a text viewer using authenticated fetch
@@ -513,8 +518,8 @@ class InlineViewer {
         }
 
         // clear
-        window.app.viewFile = null;
-        window.updateHistory(false);
+        app.viewFile = null;
+        updateHistory(false);
 
         // Clear references
         this.currentFile = null;
@@ -573,21 +578,4 @@ class InlineViewer {
     }
 }
 
-// Initialize viewer when document is ready
-document.addEventListener('DOMContentLoaded', () => {
-    // Check if it's already initialized
-    if (!window.inlineViewer) {
-        console.log('Initializing inline viewer on DOMContentLoaded');
-        window.inlineViewer = new InlineViewer();
-    }
-});
-
-// Fallback initialization for cases where DOMContentLoaded already fired
-if (document.readyState === 'complete' || document.readyState === 'interactive') {
-    if (!window.inlineViewer) {
-        console.log('Fallback initialization for inline viewer');
-        setTimeout(() => {
-            window.inlineViewer = new InlineViewer();
-        }, 100);
-    }
-}
+export const inlineViewer = new InlineViewer();
diff --git a/static/js/features/files/multiSelect.js b/static/js/features/files/multiSelect.js
index 5cae4d1d..2f98c1fc 100644
--- a/static/js/features/files/multiSelect.js
+++ b/static/js/features/files/multiSelect.js
@@ -11,6 +11,14 @@
 
 // @ts-check
 
+import { loadFiles } from '../../app/filesView.js';
+import { app } from '../../app/state.js';
+import { showConfirmDialog, ui } from '../../app/ui.js';
+import { i18n } from '../../core/i18n.js';
+import { favorites } from '../library/favorites.js';
+import { contextMenus } from './contextMenus.js';
+import { getAuthHeaders } from './fileOperations.js';
+
 const multiSelect = {
     /** Currently selected items: Map<id, { id, name, type, parentId }> */
     _selected: new Map(),
@@ -42,8 +50,8 @@ const multiSelect = {
     // ── Helpers for i18n ────────────────────────────────────
 
     _t(key, vars) {
-        if (window.i18n && typeof window.i18n.t === 'function') {
-            const val = window.i18n.t(key, vars);
+        if (i18n && typeof i18n.t === 'function') {
+            const val = i18n.t(key, vars);
             // If i18n returned the key itself, it's missing → fall back
             if (val && val !== key) return val;
         }
@@ -133,15 +141,15 @@ const multiSelect = {
     showBatchResult(action, result) {
         if (action === 'copy') {
             if (result.errors > 0) {
-                window.ui.showNotification('Batch copy', `${result.success} copied, ${result.errors} failed`);
+                ui.showNotification('Batch copy', `${result.success} copied, ${result.errors} failed`);
             } else {
-                window.ui.showNotification('Items copied', `${result.success} item${result.success !== 1 ? 's' : ''} copied successfully`);
+                ui.showNotification('Items copied', `${result.success} item${result.success !== 1 ? 's' : ''} copied successfully`);
             }
         } else {
             if (result.errors > 0) {
-                window.ui.showNotification('Batch move', `${result.success} moved, ${result.errors} failed`);
+                ui.showNotification('Batch move', `${result.success} moved, ${result.errors} failed`);
             } else {
-                window.ui.showNotification('Items moved', `${result.success} item${result.success !== 1 ? 's' : ''} moved successfully`);
+                ui.showNotification('Items moved', `${result.success} item${result.success !== 1 ? 's' : ''} moved successfully`);
             }
         }
     },
@@ -366,18 +374,18 @@ const multiSelect = {
             const errors = data.stats?.failed || 0;
 
             this.clear();
-            window.loadFiles();
+            loadFiles();
 
             if (errors > 0) {
-                window.ui.showNotification('Batch delete', `${success} moved to trash, ${errors} failed`);
+                ui.showNotification('Batch delete', `${success} moved to trash, ${errors} failed`);
             } else {
-                window.ui.showNotification('Moved to trash', `${success} item${success !== 1 ? 's' : ''} moved to trash`);
+                ui.showNotification('Moved to trash', `${success} item${success !== 1 ? 's' : ''} moved to trash`);
             }
         } catch (e) {
             console.error('Batch trash error:', e);
-            window.ui.showNotification('Error', 'Could not move items to trash');
+            ui.showNotification('Error', 'Could not move items to trash');
             this.clear();
-            window.loadFiles();
+            loadFiles();
         }
     },
 
@@ -386,9 +394,9 @@ const multiSelect = {
         const items = this.items;
         if (items.length === 0) return;
 
-        window.app.moveDialogMode = 'batch';
-        window.app.batchMoveItems = items;
-        window.app.selectedTargetFolderId = '';
+        app.moveDialogMode = 'batch';
+        app.batchMoveItems = items;
+        app.selectedTargetFolderId = '';
 
         const dialog = document.getElementById('move-file-dialog');
         const dialogHeader = dialog.querySelector('.rename-dialog-header');
@@ -406,7 +414,7 @@ const multiSelect = {
         const items = this.items;
         if (items.length === 0) return;
 
-        window.ui.showNotification('Preparing download', 'Creating ZIP archive...');
+        ui.showNotification('Preparing download', 'Creating ZIP archive...');
 
         try {
             const fileIds = items.filter((i) => i.type === 'file').map((i) => i.id);
@@ -431,20 +439,20 @@ const multiSelect = {
             URL.revokeObjectURL(url);
         } catch (e) {
             console.error('Batch download error:', e);
-            window.ui.showNotification('Error', 'Could not download selected items');
+            ui.showNotification('Error', 'Could not download selected items');
         }
     },
 
     /** Batch add to favorites — single API call */
     async batchFavorites() {
         const items = this.items;
-        if (items.length === 0 || !window.favorites) return;
+        if (items.length === 0 || !favorites) return;
 
         // Filter out items already in favourites
-        const toAdd = items.filter((i) => !window.favorites.isFavorite(i.id, i.type));
+        const toAdd = items.filter((i) => !favorites.isFavorite(i.id, i.type));
         if (toAdd.length === 0) {
             this.clear();
-            window.ui.showNotification(this._t('favorites.add') || 'Favorites', 'All selected items are already favorites');
+            ui.showNotification(this._t('favorites.add') || 'Favorites', 'All selected items are already favorites');
             return;
         }
 
@@ -463,23 +471,23 @@ const multiSelect = {
             const inserted = data.stats?.inserted || 0;
 
             // Replace cache directly from response (no extra GET)
-            if (data.favorites && window.favorites._replaceCacheFromResponse) {
-                window.favorites._replaceCacheFromResponse(data.favorites);
+            if (data.favorites && favorites._replaceCacheFromResponse) {
+                favorites._replaceCacheFromResponse(data.favorites);
             } else {
-                await window.favorites._fetchFromServer();
+                await favorites._fetchFromServer();
             }
 
             this.clear();
-            if (typeof window.loadFiles === 'function') window.loadFiles();
+            loadFiles();
 
             if (inserted > 0) {
-                window.ui.showNotification(this._t('favorites.add') || 'Added to favorites', `${inserted} item${inserted !== 1 ? 's' : ''} added to favorites`);
+                ui.showNotification(this._t('favorites.add') || 'Added to favorites', `${inserted} item${inserted !== 1 ? 's' : ''} added to favorites`);
             } else {
-                window.ui.showNotification(this._t('favorites.add') || 'Favorites', 'All selected items are already favorites');
+                ui.showNotification(this._t('favorites.add') || 'Favorites', 'All selected items are already favorites');
             }
         } catch (e) {
             console.error('Batch favorites error:', e);
-            window.ui.showNotification('Error', 'Could not add items to favorites');
+            ui.showNotification('Error', 'Could not add items to favorites');
         }
     },
 
@@ -510,8 +518,8 @@ const multiSelect = {
         const batchSelectionBar = document.getElementById('batch-selection-bar');
         batchSelectionBar.innerHTML = this._buildSelectionBarHTML();
 
-        if (window.i18n?.translateElement) {
-            window.i18n.translateElement(batchSelectionBar);
+        if (i18n?.translateElement) {
+            i18n.translateElement(batchSelectionBar);
         }
         this._wireBarButtons();
     },
@@ -524,5 +532,4 @@ const multiSelect = {
     }
 };
 
-// Expose globally
-window.multiSelect = multiSelect;
+export { multiSelect };
diff --git a/static/js/features/files/search.js b/static/js/features/files/search.js
index a52e161b..e47ad8da 100644
--- a/static/js/features/files/search.js
+++ b/static/js/features/files/search.js
@@ -7,6 +7,11 @@
  * displays the enriched results returned by the server.
  */
 
+import { loadFiles } from '../../app/filesView.js';
+import { app } from '../../app/state.js';
+import { ui } from '../../app/ui.js';
+import { getAuthHeaders } from './fileOperations.js';
+
 const search = {
     /**
      * Perform a search using query parameters.
@@ -55,7 +60,7 @@ const search = {
             }
         } catch (error) {
             console.error('Error performing search:', error);
-            window.ui.showNotification('Error', 'Error performing search');
+            ui.showNotification('Error', 'Error performing search');
             return {
                 files: [],
                 folders: [],
@@ -109,7 +114,7 @@ const search = {
      * @param {Object} results - Enriched search results from backend
      */
     displaySearchResults(results) {
-        window.ui.resetFilesList(); // ensure also list visible & error hidden
+        ui.resetFilesList(); // ensure also list visible & error hidden
         //FIXME: move into action rather bage sticky header + hide bread crumb ? + note also that search result does not consider section
         const pageStickyHeader = document.getElementById('page-sticky-header');
 
@@ -163,17 +168,17 @@ const search = {
         if (clearSearchBtn) {
             clearSearchBtn.addEventListener('click', () => {
                 document.querySelector('.search-container input').value = '';
-                window.app.currentPath = '';
-                window.app.isSearchMode = false;
+                app.currentPath = '';
+                app.isSearchMode = false;
                 document.querySelector('.search-results-header')?.remove();
-                window.ui.updateBreadcrumb('');
-                window.loadFiles();
+                ui.updateBreadcrumb('');
+                loadFiles();
             });
         }
 
         // Empty state
         if (results.files.length === 0 && results.folders.length === 0) {
-            window.ui.showError(`
+            ui.showError(`
                 <i class="fas fa-search empty-state-icon"></i>
                 <p class="search-empty-text">No results found for this search</p>
             `);
@@ -182,12 +187,12 @@ const search = {
 
         // Render folders (server-provided enriched data)
         results.folders.forEach((folder) => {
-            window.ui.addFolderToView(folder);
+            ui.addFolderToView(folder);
         });
 
         // Render files (server-provided enriched data)
         results.files.forEach((file) => {
-            window.ui.addFileToView(file);
+            ui.addFileToView(file);
         });
     },
 
@@ -203,19 +208,18 @@ const search = {
             });
 
             if (response.ok) {
-                window.ui.showNotification('Cache cleared', 'Search cache cleared successfully');
+                ui.showNotification('Cache cleared', 'Search cache cleared successfully');
                 return true;
             } else {
-                window.ui.showNotification('Error', 'Error clearing search cache');
+                ui.showNotification('Error', 'Error clearing search cache');
                 return false;
             }
         } catch (error) {
             console.error('Error clearing search cache:', error);
-            window.ui.showNotification('Error', 'Error clearing search cache');
+            ui.showNotification('Error', 'Error clearing search cache');
             return false;
         }
     }
 };
 
-// Expose the search module globally
-window.search = search;
+export { search };
diff --git a/static/js/features/files/wopiEditor.js b/static/js/features/files/wopiEditor.js
index 435f4001..7c3f487d 100644
--- a/static/js/features/files/wopiEditor.js
+++ b/static/js/features/files/wopiEditor.js
@@ -4,6 +4,9 @@
  * Opens document files in Collabora Online / OnlyOffice via WOPI protocol.
  * Supports two modes: in-app modal (default) and new browser tab.
  */
+
+import { loadFiles } from '../../app/filesView.js';
+
 class WopiEditor {
     constructor() {
         this.editorModal = null;
@@ -203,10 +206,9 @@ class WopiEditor {
             this._messageHandler = null;
         }
         this.editorModal = null;
+
         // Refresh file list to pick up any saves
-        if (typeof loadFiles === 'function') {
-            loadFiles();
-        }
+        loadFiles();
     }
 
     /**
@@ -243,7 +245,7 @@ class WopiEditor {
 }
 
 // Global instance
-window.wopiEditor = new WopiEditor();
+export const wopiEditor = new WopiEditor();
 
 // Prefetch supported extensions so canEdit() is fast on first use
-window.wopiEditor._fetchSupportedExtensions();
+wopiEditor._fetchSupportedExtensions();
diff --git a/static/js/features/library/favorites.js b/static/js/features/library/favorites.js
index 91e24eb8..579e8a43 100644
--- a/static/js/features/library/favorites.js
+++ b/static/js/features/library/favorites.js
@@ -6,6 +6,10 @@
  * rendering path so star icons can be painted without a round-trip.
  */
 
+import { ui } from '../../app/ui.js';
+import { getCsrfHeaders } from '../../core/csrf.js';
+import { i18n } from '../../core/i18n.js';
+
 const favorites = {
     /** @type {Map<string, object>} key = "file:<id>" | "folder:<id>" */
     _cache: new Map(),
@@ -104,10 +108,10 @@ const favorites = {
             await this._fetchFromServer();
 
             // Notify user
-            if (window.ui?.showNotification) {
-                window.ui.showNotification(
-                    window.i18n ? window.i18n.t('favorites.added_title') : 'Added to favorites',
-                    `"${name}" ${window.i18n ? window.i18n.t('favorites.added_msg') : 'added to favorites'}`
+            if (ui?.showNotification) {
+                ui.showNotification(
+                    i18n ? i18n.t('favorites.added_title') : 'Added to favorites',
+                    `"${name}" ${i18n ? i18n.t('favorites.added_msg') : 'added to favorites'}`
                 );
             }
 
@@ -139,10 +143,10 @@ const favorites = {
             // Remove from local cache
             this._cache.delete(this._cacheKey(id, type));
 
-            if (window.ui?.showNotification) {
-                window.ui.showNotification(
-                    window.i18n ? window.i18n.t('favorites.removed_title') : 'Removed from favorites',
-                    `"${itemName}" ${window.i18n ? window.i18n.t('favorites.removed_msg') : 'removed from favorites'}`
+            if (ui?.showNotification) {
+                ui.showNotification(
+                    i18n ? i18n.t('favorites.removed_title') : 'Removed from favorites',
+                    `"${itemName}" ${i18n ? i18n.t('favorites.removed_msg') : 'removed from favorites'}`
                 );
             }
 
@@ -167,14 +171,14 @@ const favorites = {
                 await this._fetchFromServer();
             }
 
-            window.ui.resetFilesList(); // ensure also list visible & error hidden
-            window.ui.updateBreadcrumb('');
+            ui.resetFilesList(); // ensure also list visible & error hidden
+            ui.updateBreadcrumb('');
 
             if (this._cache.size === 0) {
-                window.ui.showError(`
+                ui.showError(`
                     <i class="fas fa-star empty-state-icon"></i>
-                    <p>${window.i18n ? window.i18n.t('favorites.empty_state') : 'No favorite items'}</p>
-                    <p>${window.i18n ? window.i18n.t('favorites.empty_hint') : 'To mark as favorite, right-click on any file or folder'}</p>
+                    <p>${i18n ? i18n.t('favorites.empty_state') : 'No favorite items'}</p>
+                    <p>${i18n ? i18n.t('favorites.empty_hint') : 'To mark as favorite, right-click on any file or folder'}</p>
                 `);
                 return;
             }
@@ -204,16 +208,15 @@ const favorites = {
                     });
                 }
             }
-            if (folders.length) window.ui.renderFolders(folders);
-            if (files.length) window.ui.renderFiles(files);
+            if (folders.length) ui.renderFolders(folders);
+            if (files.length) ui.renderFiles(files);
         } catch (error) {
             console.error('Error displaying favorites:', error);
-            if (window.ui?.showNotification) {
-                window.ui.showNotification('Error', 'Error loading favorite items');
+            if (ui?.showNotification) {
+                ui.showNotification('Error', 'Error loading favorite items');
             }
         }
     }
 };
 
-// Expose globally
-window.favorites = favorites;
+export { favorites };
diff --git a/static/js/features/library/music.js b/static/js/features/library/music.js
index 0a77dd3f..456ec605 100644
--- a/static/js/features/library/music.js
+++ b/static/js/features/library/music.js
@@ -1,3 +1,11 @@
+import { app } from '../../app/state.js';
+import { getCsrfHeaders } from '../../core/csrf.js';
+import { formatFileSize } from '../../core/formatters.js';
+import { i18n } from '../../core/i18n.js';
+import { oxiIcon } from '../../core/icons.js';
+import { Modal } from '../../core/modal.js';
+import { notifications } from '../../core/notifications.js';
+
 /**
  * OxiCloud - Music Library View
  * Playlist management with track listings and audio player
@@ -13,7 +21,7 @@ const musicView = {
     selected: new Set(),
 
     _headers(json = false) {
-        const h = typeof getCsrfHeaders === 'function' ? { ...getCsrfHeaders() } : {};
+        const h = { ...getCsrfHeaders() };
         if (json) h['Content-Type'] = 'application/json';
         return h;
     },
@@ -78,8 +86,9 @@ const musicView = {
     _renderPlaylists() {
         if (!this._container) return;
 
-        const t = (key, fallback = '') => {
-            return typeof i18n !== 'undefined' && i18n.t ? i18n.t(key) : fallback || key;
+        // FIXME should call directly
+        const t = (key, _fallback = '') => {
+            return i18n.t(key);
         };
 
         // Empty state: no playlists at all — show full-width centered onboarding
@@ -178,7 +187,7 @@ const musicView = {
         if (!listEl) return;
 
         const t = (key, fallback = '') => {
-            return typeof i18n !== 'undefined' && i18n.t ? i18n.t(key) : fallback || key;
+            return i18n?.t ? i18n.t(key) : fallback || key;
         };
 
         if (this.playlists.length === 0) {
@@ -283,7 +292,7 @@ const musicView = {
         if (nameEl) nameEl.textContent = playlist.name;
         if (metaEl) {
             const t = (key, fallback = '') => {
-                return typeof i18n !== 'undefined' && i18n.t ? i18n.t(key) : fallback || key;
+                return i18n?.t ? i18n.t(key) : fallback || key;
             };
             metaEl.textContent = `${playlist.track_count || 0} ${t('music.tracks', 'tracks')}`;
         }
@@ -305,7 +314,7 @@ const musicView = {
         }
         const togglePublicBtn = document.getElementById('music-toggle-public-btn');
         if (togglePublicBtn) {
-            const t2 = (key, fallback = '') => (typeof i18n !== 'undefined' && i18n.t ? i18n.t(key) : fallback || key);
+            const t2 = (key, fallback = '') => (i18n?.t ? i18n.t(key) : fallback || key);
             togglePublicBtn.title = playlist.is_public ? t2('music.make_private', 'Make private') : t2('music.make_public', 'Make public');
             togglePublicBtn.classList.toggle('active', playlist.is_public);
         }
@@ -344,7 +353,7 @@ const musicView = {
         if (!trackListEl) return;
 
         const t = (key, fallback = '') => {
-            return typeof i18n !== 'undefined' && i18n.t ? i18n.t(key) : fallback || key;
+            return i18n?.t ? i18n.t(key) : fallback || key;
         };
 
         if (this.currentTracks.length === 0) {
@@ -459,7 +468,7 @@ const musicView = {
         if (!this.currentTracks[idx]) return;
 
         const t = (key, fallback = '') => {
-            return typeof i18n !== 'undefined' && i18n.t ? i18n.t(key) : fallback || key;
+            return i18n?.t ? i18n.t(key) : fallback || key;
         };
         musicPlayer.setQueue(this.currentTracks, this.currentPlaylist?.name || t('music.playlists', 'Playlist'));
         musicPlayer.playTrack(idx);
@@ -479,7 +488,7 @@ const musicView = {
                 [shuffled[i], shuffled[j]] = [shuffled[j], shuffled[i]];
             }
             const t = (key, fallback = '') => {
-                return typeof i18n !== 'undefined' && i18n.t ? i18n.t(key) : fallback || key;
+                return i18n?.t ? i18n.t(key) : fallback || key;
             };
             musicPlayer.setQueue(shuffled, this.currentPlaylist?.name || t('music.shuffle', 'Shuffle'));
             musicPlayer.playTrack(0);
@@ -488,11 +497,10 @@ const musicView = {
 
     async _showCreatePlaylistDialog() {
         const t = (key, fallback = '') => {
-            return typeof i18n !== 'undefined' && i18n.t ? i18n.t(key) : fallback || key;
+            return i18n?.t ? i18n.t(key) : fallback || key;
         };
 
-        if (!window.Modal) return;
-        const name = await window.Modal.prompt({
+        const name = await Modal.prompt({
             title: t('music.create_playlist', 'Create Playlist'),
             label: t('music.playlist_name', 'Playlist name'),
             placeholder: t('music.playlist_name', 'Playlist name'),
@@ -506,7 +514,7 @@ const musicView = {
 
     async _createPlaylist(name) {
         const t = (key, fallback = '') => {
-            return typeof i18n !== 'undefined' && i18n.t ? i18n.t(key) : fallback || key;
+            return i18n?.t ? i18n.t(key) : fallback || key;
         };
         const createBtn = document.getElementById('music-create-playlist-btn');
         if (createBtn) createBtn.disabled = true;
@@ -524,8 +532,8 @@ const musicView = {
             this.playlists.unshift(playlist);
             this._renderPlaylists();
             this._selectPlaylist(playlist.id);
-            if (window.notifications) {
-                window.notifications.addNotification({
+            if (notifications) {
+                notifications.addNotification({
                     icon: 'fa-check-circle',
                     iconClass: 'upload',
                     title: t('music.create_playlist', 'Create Playlist'),
@@ -534,8 +542,8 @@ const musicView = {
             }
         } catch (err) {
             console.error('Create playlist error:', err);
-            if (window.notifications) {
-                window.notifications.addNotification({
+            if (notifications) {
+                notifications.addNotification({
                     icon: 'fa-exclamation-circle',
                     iconClass: 'error',
                     title: t('music.error', 'Error'),
@@ -549,17 +557,13 @@ const musicView = {
 
     async _deletePlaylist() {
         const t = (key, fallback = '') => {
-            return typeof i18n !== 'undefined' && i18n.t ? i18n.t(key) : fallback || key;
+            return i18n?.t ? i18n.t(key) : fallback || key;
         };
 
         if (!this.currentPlaylist) return;
 
         const confirmed = await new Promise((resolve) => {
-            if (!window.Modal) {
-                resolve(confirm(t('music.confirm_delete', 'Delete this playlist?')));
-                return;
-            }
-            window.Modal.prompt({
+            Modal.prompt({
                 title: t('music.delete', 'Delete'),
                 label: t('music.confirm_delete', 'Delete this playlist?'),
                 placeholder: '',
@@ -586,13 +590,13 @@ const musicView = {
             this.currentPlaylist = null;
             this.currentTracks = [];
             this._renderPlaylists();
-            if (window.notifications) {
-                window.notifications.addNotification({ icon: 'fa-check-circle', iconClass: 'upload', title: t('music.delete', 'Delete'), text: deletedName });
+            if (notifications) {
+                notifications.addNotification({ icon: 'fa-check-circle', iconClass: 'upload', title: t('music.delete', 'Delete'), text: deletedName });
             }
         } catch (err) {
             console.error('Delete playlist error:', err);
-            if (window.notifications) {
-                window.notifications.addNotification({
+            if (notifications) {
+                notifications.addNotification({
                     icon: 'fa-exclamation-circle',
                     iconClass: 'error',
                     title: t('music.error', 'Error'),
@@ -641,11 +645,10 @@ const musicView = {
     async _showEditPlaylistDialog() {
         if (!this.currentPlaylist) return;
         const t = (key, fallback = '') => {
-            return typeof i18n !== 'undefined' && i18n.t ? i18n.t(key) : fallback || key;
+            return i18n?.t ? i18n.t(key) : fallback || key;
         };
 
-        if (!window.Modal) return;
-        const newName = await window.Modal.prompt({
+        const newName = await Modal.prompt({
             title: t('music.edit', 'Edit'),
             label: t('music.playlist_name', 'Playlist name'),
             placeholder: t('music.playlist_name', 'Playlist name'),
@@ -674,8 +677,8 @@ const musicView = {
             this._renderPlaylistList();
         } catch (err) {
             console.error('Edit playlist error:', err);
-            if (window.notifications) {
-                window.notifications.addNotification({
+            if (notifications) {
+                notifications.addNotification({
                     icon: 'fa-exclamation-circle',
                     iconClass: 'error',
                     title: t('music.error', 'Error'),
@@ -688,11 +691,10 @@ const musicView = {
     async _showSharePlaylistDialog() {
         if (!this.currentPlaylist) return;
         const t = (key, fallback = '') => {
-            return typeof i18n !== 'undefined' && i18n.t ? i18n.t(key) : fallback || key;
+            return i18n?.t ? i18n.t(key) : fallback || key;
         };
 
-        if (!window.Modal) return;
-        const userId = await window.Modal.prompt({
+        const userId = await Modal.prompt({
             title: t('music.share', 'Share'),
             label: t('music.share_with_user', 'User ID or email'),
             placeholder: t('music.share_with_user', 'User ID or email'),
@@ -711,8 +713,8 @@ const musicView = {
 
             if (!resp.ok) throw new Error('Failed to share playlist');
 
-            if (window.notifications) {
-                window.notifications.addNotification({
+            if (notifications) {
+                notifications.addNotification({
                     icon: 'fa-check-circle',
                     iconClass: 'upload',
                     title: t('music.share', 'Share'),
@@ -721,8 +723,8 @@ const musicView = {
             }
         } catch (err) {
             console.error('Share playlist error:', err);
-            if (window.notifications) {
-                window.notifications.addNotification({
+            if (notifications) {
+                notifications.addNotification({
                     icon: 'fa-exclamation-circle',
                     iconClass: 'error',
                     title: t('music.error', 'Error'),
@@ -735,7 +737,7 @@ const musicView = {
     async _showAddTracksDialog() {
         if (!this.currentPlaylist) return;
         const t = (key, fallback = '') => {
-            return typeof i18n !== 'undefined' && i18n.t ? i18n.t(key) : fallback || key;
+            return i18n?.t ? i18n.t(key) : fallback || key;
         };
 
         // ── Build modal overlay ──
@@ -813,7 +815,7 @@ const musicView = {
             for (const file of files) {
                 const row = document.createElement('label');
                 row.className = `music-picker-item${selectedIds.has(file.id) ? ' selected' : ''}`;
-                const sizeStr = file.size != null && window.formatFileSize ? window.formatFileSize(file.size) : '';
+                const sizeStr = file.size != null && formatFileSize ? formatFileSize(file.size) : '';
                 row.innerHTML = `
                     <input type="checkbox" value="${file.id}" ${selectedIds.has(file.id) ? 'checked' : ''}>
                     <i class="fas fa-file-audio"></i>
@@ -858,8 +860,8 @@ const musicView = {
                 });
                 if (!resp.ok) throw new Error('Failed to add tracks');
 
-                if (window.notifications) {
-                    window.notifications.addNotification({
+                if (notifications) {
+                    notifications.addNotification({
                         icon: 'fa-check-circle',
                         iconClass: 'upload',
                         title: t('music.add_tracks', 'Add Tracks'),
@@ -878,8 +880,8 @@ const musicView = {
                 }
             } catch (err) {
                 console.error('Add tracks error:', err);
-                if (window.notifications) {
-                    window.notifications.addNotification({
+                if (notifications) {
+                    notifications.addNotification({
                         icon: 'fa-exclamation-circle',
                         iconClass: 'error',
                         title: t('music.error', 'Error'),
@@ -898,7 +900,7 @@ const musicView = {
 
     async _removeTrackFromPlaylist(_trackId, fileId) {
         if (!this.currentPlaylist) return;
-        const t = (key, fallback = '') => (typeof i18n !== 'undefined' && i18n.t ? i18n.t(key) : fallback || key);
+        const t = (key, fallback = '') => (i18n?.t ? i18n.t(key) : fallback || key);
 
         try {
             const resp = await fetch(`/api/playlists/${this.currentPlaylist.id}/tracks/${encodeURIComponent(fileId)}`, {
@@ -908,8 +910,8 @@ const musicView = {
             });
             if (!resp.ok) throw new Error('Failed to remove track');
 
-            if (window.notifications) {
-                window.notifications.addNotification({
+            if (notifications) {
+                notifications.addNotification({
                     icon: 'fa-check-circle',
                     iconClass: 'upload',
                     title: t('music.remove', 'Remove'),
@@ -927,8 +929,8 @@ const musicView = {
             }
         } catch (err) {
             console.error('Remove track error:', err);
-            if (window.notifications) {
-                window.notifications.addNotification({
+            if (notifications) {
+                notifications.addNotification({
                     icon: 'fa-exclamation-circle',
                     iconClass: 'error',
                     title: t('music.error', 'Error'),
@@ -940,7 +942,7 @@ const musicView = {
 
     async _reorderTrack(fromIdx, toIdx) {
         if (!this.currentPlaylist) return;
-        const t = (key, fallback = '') => (typeof i18n !== 'undefined' && i18n.t ? i18n.t(key) : fallback || key);
+        const t = (key, fallback = '') => (i18n?.t ? i18n.t(key) : fallback || key);
 
         const tracks = [...this.currentTracks];
         const [moved] = tracks.splice(fromIdx, 1);
@@ -959,8 +961,8 @@ const musicView = {
             if (!resp.ok) throw new Error('Failed to reorder tracks');
         } catch (err) {
             console.error('Reorder error:', err);
-            if (window.notifications) {
-                window.notifications.addNotification({
+            if (notifications) {
+                notifications.addNotification({
                     icon: 'fa-exclamation-circle',
                     iconClass: 'error',
                     title: t('music.error', 'Error'),
@@ -973,7 +975,7 @@ const musicView = {
 
     async _showManageSharesDialog() {
         if (!this.currentPlaylist) return;
-        const t = (key, fallback = '') => (typeof i18n !== 'undefined' && i18n.t ? i18n.t(key) : fallback || key);
+        const t = (key, fallback = '') => (i18n?.t ? i18n.t(key) : fallback || key);
 
         const existing = document.getElementById('music-shares-dialog');
         if (existing) existing.remove();
@@ -1025,8 +1027,8 @@ const musicView = {
                 userInput.value = '';
                 writeInput.checked = false;
                 this._loadSharesList(dialog);
-                if (window.notifications) {
-                    window.notifications.addNotification({
+                if (notifications) {
+                    notifications.addNotification({
                         icon: 'fa-check-circle',
                         iconClass: 'upload',
                         title: t('music.share', 'Share'),
@@ -1034,8 +1036,8 @@ const musicView = {
                     });
                 }
             } catch (err) {
-                if (window.notifications) {
-                    window.notifications.addNotification({
+                if (notifications) {
+                    notifications.addNotification({
                         icon: 'fa-exclamation-circle',
                         iconClass: 'error',
                         title: t('music.error', 'Error'),
@@ -1050,7 +1052,7 @@ const musicView = {
 
     async _loadSharesList(dialog) {
         if (!this.currentPlaylist) return;
-        const t = (key, fallback = '') => (typeof i18n !== 'undefined' && i18n.t ? i18n.t(key) : fallback || key);
+        const t = (key, fallback = '') => (i18n?.t ? i18n.t(key) : fallback || key);
         const body = dialog.querySelector('.music-shares-body');
         if (!body) return;
 
@@ -1095,7 +1097,7 @@ const musicView = {
 
     async _removeShare(userId, dialog) {
         if (!this.currentPlaylist) return;
-        const t = (key, fallback = '') => (typeof i18n !== 'undefined' && i18n.t ? i18n.t(key) : fallback || key);
+        const t = (key, fallback = '') => (i18n?.t ? i18n.t(key) : fallback || key);
 
         try {
             const resp = await fetch(`/api/playlists/${this.currentPlaylist.id}/share/${encodeURIComponent(userId)}`, {
@@ -1106,8 +1108,8 @@ const musicView = {
             if (!resp.ok) throw new Error('Failed to remove share');
             this._loadSharesList(dialog);
         } catch (err) {
-            if (window.notifications) {
-                window.notifications.addNotification({
+            if (notifications) {
+                notifications.addNotification({
                     icon: 'fa-exclamation-circle',
                     iconClass: 'error',
                     title: t('music.error', 'Error'),
@@ -1119,7 +1121,7 @@ const musicView = {
 
     async _togglePublic() {
         if (!this.currentPlaylist) return;
-        const t = (key, fallback = '') => (typeof i18n !== 'undefined' && i18n.t ? i18n.t(key) : fallback || key);
+        const t = (key, fallback = '') => (i18n?.t ? i18n.t(key) : fallback || key);
         const newValue = !this.currentPlaylist.is_public;
 
         try {
@@ -1144,9 +1146,9 @@ const musicView = {
                 btn.classList.toggle('active', newValue);
             }
 
-            if (window.notifications) {
+            if (notifications) {
                 const status = newValue ? t('music.public', 'Public') : t('music.private', 'Private');
-                window.notifications.addNotification({
+                notifications.addNotification({
                     icon: 'fa-check-circle',
                     iconClass: 'upload',
                     title: t('music.toggle_public', 'Visibility'),
@@ -1155,8 +1157,8 @@ const musicView = {
             }
         } catch (err) {
             console.error('Toggle public error:', err);
-            if (window.notifications) {
-                window.notifications.addNotification({
+            if (notifications) {
+                notifications.addNotification({
                     icon: 'fa-exclamation-circle',
                     iconClass: 'error',
                     title: t('music.error', 'Error'),
@@ -1168,7 +1170,7 @@ const musicView = {
 
     async _showCoverPicker() {
         if (!this.currentPlaylist) return;
-        const t = (key, fallback = '') => (typeof i18n !== 'undefined' && i18n.t ? i18n.t(key) : fallback || key);
+        const t = (key, fallback = '') => (i18n?.t ? i18n.t(key) : fallback || key);
 
         const input = document.createElement('input');
         input.type = 'file';
@@ -1184,13 +1186,13 @@ const musicView = {
             try {
                 const formData = new FormData();
                 formData.append('file', file);
-                const folderId = window.app?.currentPath || window.app?.userHomeFolderId || '';
+                const folderId = app?.currentPath || app?.userHomeFolderId || '';
                 formData.append('folder_id', folderId);
 
                 const uploadResp = await fetch('/api/files/upload', {
                     method: 'POST',
                     credentials: 'include',
-                    headers: typeof getCsrfHeaders === 'function' ? getCsrfHeaders() : {},
+                    headers: getCsrfHeaders(),
                     body: formData
                 });
                 if (!uploadResp.ok) throw new Error('Upload failed');
@@ -1214,8 +1216,8 @@ const musicView = {
                     coverEl.innerHTML = `<img src="/api/files/${encodeURIComponent(uploaded.id)}" alt="" class="music-cover-img"><div class="music-cover-overlay"><i class="fas fa-camera"></i></div>`;
                 }
 
-                if (window.notifications) {
-                    window.notifications.addNotification({
+                if (notifications) {
+                    notifications.addNotification({
                         icon: 'fa-check-circle',
                         iconClass: 'upload',
                         title: t('music.set_cover', 'Set cover'),
@@ -1224,8 +1226,8 @@ const musicView = {
                 }
             } catch (err) {
                 console.error('Cover upload error:', err);
-                if (window.notifications) {
-                    window.notifications.addNotification({
+                if (notifications) {
+                    notifications.addNotification({
                         icon: 'fa-exclamation-circle',
                         iconClass: 'error',
                         title: t('music.error', 'Error'),
@@ -1647,11 +1649,11 @@ const musicPlayer = {
         this.isPlaying = false;
         this._updateUI();
         const t = (key, fallback = '') => {
-            return typeof i18n !== 'undefined' && i18n.t ? i18n.t(key) : fallback || key;
+            return i18n?.t ? i18n.t(key) : fallback || key;
         };
-        if (window.notifications) {
+        if (notifications) {
             const trackName = this.currentTrack?.title || this.currentTrack?.file_name || t('music.unknown_title', 'Unknown');
-            window.notifications.addNotification({
+            notifications.addNotification({
                 icon: 'fa-exclamation-circle',
                 iconClass: 'error',
                 title: t('music.error', 'Error'),
@@ -1670,8 +1672,8 @@ const musicPlayer = {
             if (icon) {
                 const iconName = this.isPlaying ? 'pause' : 'play';
                 const extraClass = 'player-btn-main';
-                if (window.oxiIcon) {
-                    icon.outerHTML = window.oxiIcon(iconName, extraClass);
+                if (oxiIcon) {
+                    icon.outerHTML = oxiIcon(iconName, extraClass);
                 } else {
                     icon.className = `fas fa-${iconName} ${extraClass}`;
                 }
@@ -1680,7 +1682,7 @@ const musicPlayer = {
 
         if (trackName) {
             const t = (key, fallback = '') => {
-                return typeof i18n !== 'undefined' && i18n.t ? i18n.t(key) : fallback || key;
+                return i18n?.t ? i18n.t(key) : fallback || key;
             };
             trackName.textContent = this.currentTrack
                 ? this.currentTrack.title || this.currentTrack.file_name || t('music.unknown_title', 'Unknown')
@@ -1704,8 +1706,8 @@ const musicPlayer = {
                     if (playIcon) playIcon.classList.remove('hidden');
                     if (playIcon) {
                         const iconName = this.isPlaying ? 'pause' : 'play';
-                        if (window.oxiIcon) {
-                            playIcon.outerHTML = window.oxiIcon(iconName, 'track-play-icon');
+                        if (oxiIcon) {
+                            playIcon.outerHTML = oxiIcon(iconName, 'track-play-icon');
                         } else {
                             playIcon.className = `fas fa-${iconName} track-play-icon`;
                         }
@@ -1735,7 +1737,7 @@ const musicPlayer = {
         if (!queueList) return;
 
         const t = (key, fallback = '') => {
-            return typeof i18n !== 'undefined' && i18n.t ? i18n.t(key) : fallback || key;
+            return i18n?.t ? i18n.t(key) : fallback || key;
         };
 
         if (this.queue.length === 0) {
@@ -1838,4 +1840,4 @@ const musicPlayer = {
     }
 };
 
-window.musicView = musicView;
+export { musicView };
diff --git a/static/js/features/library/photos.js b/static/js/features/library/photos.js
index 410b2920..2c5e89b3 100644
--- a/static/js/features/library/photos.js
+++ b/static/js/features/library/photos.js
@@ -3,6 +3,10 @@
  * Photo grid grouped by day/month/year, with infinite scroll and multi-select.
  */
 
+import { getCsrfHeaders } from '../../core/csrf.js';
+import { i18n } from '../../core/i18n.js';
+import { photosLightbox } from './photosLightbox.js';
+
 const photosView = {
     /** @type {Array} All loaded photo items */
     items: [],
@@ -37,7 +41,7 @@ const photosView = {
 
     /** Auth headers (HttpOnly cookies) */
     _headers(json = false) {
-        const h = typeof getCsrfHeaders === 'function' ? { ...getCsrfHeaders() } : {};
+        const h = getCsrfHeaders();
         if (json) h['Content-Type'] = 'application/json';
         return h;
     },
@@ -406,7 +410,7 @@ const photosView = {
 
     /** Render the group mode toolbar */
     _renderToolbar() {
-        const t = (k, d) => (window.i18n ? window.i18n.t(k) : d);
+        const t = (k, d) => (i18n ? i18n.t(k) : d);
         const modes = [
             ['daily', t('photos.view_daily', 'Day')],
             ['monthly', t('photos.view_monthly', 'Month')],
@@ -423,7 +427,7 @@ const photosView = {
 
     /** Render empty state */
     _renderEmpty() {
-        const t = (k, d) => (window.i18n ? window.i18n.t(k) : d);
+        const t = (k, d) => (i18n ? i18n.t(k) : d);
         this._container.innerHTML = `
             <div class="photos-empty">
                 <i class="fas fa-images"></i>
@@ -483,8 +487,8 @@ const photosView = {
 
         // Otherwise open lightbox
         const idx = this.items.findIndex((f) => f.id === id);
-        if (idx >= 0 && window.photosLightbox) {
-            window.photosLightbox.open(this.items, idx);
+        if (idx >= 0) {
+            photosLightbox.open(this.items, idx);
         }
     },
 
@@ -516,7 +520,7 @@ const photosView = {
             document.body.appendChild(bar);
         }
 
-        const t = (k, d) => (window.i18n ? window.i18n.t(k) : d);
+        const t = (k, d) => (i18n ? i18n.t(k) : d);
         const count = this.selected.size;
         bar.innerHTML = `
             <span class="selection-count">${count} ${t('photos.items_selected', 'selected')}</span>
@@ -605,4 +609,6 @@ const photosView = {
     }
 };
 
-window.photosView = photosView;
+photosLightbox.setPhotosView(photosView);
+
+export { photosView };
diff --git a/static/js/features/library/photosLightbox.js b/static/js/features/library/photosLightbox.js
index bb661ca1..c21e73d9 100644
--- a/static/js/features/library/photosLightbox.js
+++ b/static/js/features/library/photosLightbox.js
@@ -3,7 +3,10 @@
  * Full-screen image/video viewer with prev/next navigation.
  */
 
-const photosLightbox = {
+import { getCsrfHeaders } from '../../core/csrf.js';
+import { favorites } from '../library/favorites.js';
+
+export const photosLightbox = {
     /** @type {Array} Items array reference */
     items: [],
     /** @type {number} Current index */
@@ -14,10 +17,20 @@ const photosLightbox = {
     _blobUrl: null,
     /** @type {Function|null} */
     _keyHandler: null,
+    /** @type {Object|null} Reference to photosView, set after both modules load */
+    _photosView: null,
+
+    /**
+     * Register the photosView reference (called from photos.js to avoid circular imports).
+     * @param {Object} pv
+     */
+    setPhotosView(pv) {
+        this._photosView = pv;
+    },
 
     /** Auth headers */
     _headers() {
-        return typeof getCsrfHeaders === 'function' ? { ...getCsrfHeaders() } : {};
+        return getCsrfHeaders();
     },
 
     /** Open lightbox at given index */
@@ -202,7 +215,7 @@ const photosLightbox = {
     /** Toggle favorite on current item */
     async _toggleFavorite() {
         const item = this.items[this.index];
-        if (!item || !window.favorites) return;
+        if (!item || !favorites) return;
         try {
             await fetch(`/api/favorites/file/${item.id}`, {
                 method: 'POST',
@@ -235,17 +248,17 @@ const photosLightbox = {
                 headers: this._headers()
             });
             // Remove from photosView items too
-            if (window.photosView) {
-                window.photosView.items = window.photosView.items.filter((f) => f.id !== item.id);
+            if (this._photosView) {
+                this._photosView.items = this._photosView.items.filter((f) => f.id !== item.id);
             }
             this.items.splice(this.index, 1);
             if (this.items.length === 0) {
                 this.close();
-                if (window.photosView) window.photosView._render();
+                if (this._photosView) this._photosView._render();
             } else {
                 if (this.index >= this.items.length) this.index = this.items.length - 1;
                 this._show();
-                if (window.photosView) window.photosView._render();
+                if (this._photosView) this._photosView._render();
             }
         } catch (err) {
             console.error('Delete failed:', err);
@@ -282,5 +295,3 @@ const photosLightbox = {
             .replace(/</g, '&lt;');
     }
 };
-
-window.photosLightbox = photosLightbox;
diff --git a/static/js/features/library/recent.js b/static/js/features/library/recent.js
index 129284b4..ef365218 100644
--- a/static/js/features/library/recent.js
+++ b/static/js/features/library/recent.js
@@ -6,6 +6,11 @@
  * No localStorage usage — the server persists and prunes recent items.
  */
 
+import { ui } from '../../app/ui.js';
+import { getCsrfHeaders } from '../../core/csrf.js';
+import { i18n } from '../../core/i18n.js';
+import { multiSelect } from '../files/multiSelect.js';
+
 const recent = {
     /** Maximum items to request from the server */
     MAX_RECENT_FILES: 20,
@@ -86,7 +91,7 @@ const recent = {
 
             const recentItems = await response.json();
 
-            window.ui.resetFilesList(); // ensure also list visible & error hidden
+            ui.resetFilesList(); // ensure also list visible & error hidden
             const filesList = document.getElementById('files-list');
 
             filesList.innerHTML = `
@@ -100,17 +105,17 @@ const recent = {
                 </div>
             `;
 
-            if (window.multiSelect) {
-                window.multiSelect.clear();
-                window.multiSelect.init(); // this will wire buttons & select-all-checkbox
+            if (multiSelect) {
+                multiSelect.clear();
+                multiSelect.init(); // this will wire buttons & select-all-checkbox
             }
-            window.ui.updateBreadcrumb('');
+            ui.updateBreadcrumb('');
 
             if (recentItems.length === 0) {
-                window.ui.showError(`
+                ui.showError(`
                     <i class="fas fa-clock empty-state-icon"></i>
-                    <p>${window.i18n ? window.i18n.t('recent.empty_state') : 'No recent files'}</p>
-                    <p>${window.i18n ? window.i18n.t('recent.empty_hint') : 'Files you open will appear here'}</p>
+                    <p>${i18n ? i18n.t('recent.empty_state') : 'No recent files'}</p>
+                    <p>${i18n ? i18n.t('recent.empty_hint') : 'Files you open will appear here'}</p>
                 `);
             }
 
@@ -140,16 +145,15 @@ const recent = {
                     });
                 }
             }
-            if (folders.length) window.ui.renderFolders(folders);
-            if (files.length) window.ui.renderFiles(files);
+            if (folders.length) ui.renderFolders(folders);
+            if (files.length) ui.renderFiles(files);
         } catch (error) {
             console.error('Error displaying recent files:', error);
-            if (window.ui?.showNotification) {
-                window.ui.showNotification('Error', 'Error loading recent files');
+            if (ui?.showNotification) {
+                ui.showNotification('Error', 'Error loading recent files');
             }
         }
     }
 };
 
-// Expose globally
-window.recent = recent;
+export { recent };
diff --git a/static/js/features/sharing/fileSharing.js b/static/js/features/sharing/fileSharing.js
index 12fe4baf..54f72a45 100644
--- a/static/js/features/sharing/fileSharing.js
+++ b/static/js/features/sharing/fileSharing.js
@@ -4,6 +4,11 @@
  * No localStorage is used for share data.
  */
 
+import { switchToSharedSection } from '../../app/navigation.js';
+import { ui } from '../../app/ui.js';
+import { getCsrfHeaders } from '../../core/csrf.js';
+import { formatDateTime } from '../../core/formatters.js';
+
 const fileSharing = {
     /** Auth header helper — tokens are in HttpOnly cookies now */
     _headers(json = true) {
@@ -149,11 +154,11 @@ const fileSharing = {
     async copyLinkToClipboard(url) {
         try {
             await navigator.clipboard.writeText(url);
-            window.ui.showNotification('Link copied', 'Link copied to clipboard');
+            ui.showNotification('Link copied', 'Link copied to clipboard');
             return true;
         } catch (error) {
             console.error('Error copying to clipboard:', error);
-            window.ui.showNotification('Error', 'Could not copy link');
+            ui.showNotification('Error', 'Could not copy link');
             return false;
         }
     },
@@ -165,7 +170,7 @@ const fileSharing = {
      */
     formatExpirationDate(value) {
         if (!value) return 'No expiration';
-        return window.formatDateTime(value);
+        return formatDateTime(value);
     },
 
     /**
@@ -178,9 +183,7 @@ const fileSharing = {
     async sendShareNotification(shareUrl, recipientEmail, _message = '') {
         // TODO: implement backend endpoint for email notifications
         console.log(`Share notification for ${shareUrl} sent to ${recipientEmail}`);
-        if (window.ui) {
-            window.ui.showNotification('Notification sent', `Notification sent to ${recipientEmail}`);
-        }
+        ui.showNotification('Notification sent', `Notification sent to ${recipientEmail}`);
         return true;
     },
 
@@ -193,20 +196,11 @@ const fileSharing = {
             const span = item.querySelector('span');
             if (span && span.getAttribute('data-i18n') === 'nav.shared') {
                 item.addEventListener('click', () => {
-                    if (window.switchToSharedSection) {
-                        window.switchToSharedSection();
-                    }
+                    switchToSharedSection();
                 });
             }
         });
     }
 };
 
-// Expose module globally
-window.fileSharing = fileSharing;
-
-// Global convenience functions that delegate to the module
-window.getSharedLinks = () => fileSharing.getSharedLinks();
-window.updateSharedLink = (id, data) => fileSharing.updateSharedLink(id, data);
-window.removeSharedLink = (id) => fileSharing.removeSharedLink(id);
-window.sendShareNotification = (url, email, msg) => fileSharing.sendShareNotification(url, email, msg);
+export { fileSharing };
diff --git a/static/js/views/admin/admin.js b/static/js/views/admin/admin.js
index c8478428..23f0dca5 100644
--- a/static/js/views/admin/admin.js
+++ b/static/js/views/admin/admin.js
@@ -1,3 +1,7 @@
+import { getCsrfHeaders } from '../../core/csrf.js';
+import { escapeHtml } from '../../core/formatters.js';
+import { i18n } from '../../core/i18n.js';
+
 const API = '/api';
 let currentAdminId = '';
 let usersPage = 0;
@@ -6,7 +10,7 @@ let totalUsers = 0;
 
 /* ── i18n helper — falls back to key if i18n not ready ── */
 function t(key, params) {
-    if (window.i18n && typeof window.i18n.t === 'function') return window.i18n.t(key, params);
+    if (i18n && typeof i18n.t === 'function') return i18n.t(key, params);
     // fallback: strip prefix and humanise
     return key.split('.').pop().replace(/_/g, ' ');
 }
@@ -748,13 +752,13 @@ function showAccessDenied() {
 
 /* ── Apply i18n when translations load / change ── */
 document.addEventListener('translationsLoaded', () => {
-    if (window.i18n?.translatePage) window.i18n.translatePage();
+    if (i18n?.translatePage) i18n.translatePage();
     // Re-render dynamic content that uses t()
     loadDashboard();
     if (activeTabName === 'users') loadUsers();
 });
 document.addEventListener('localeChanged', () => {
-    if (window.i18n?.translatePage) window.i18n.translatePage();
+    if (i18n?.translatePage) i18n.translatePage();
     loadDashboard();
     if (activeTabName === 'users') loadUsers();
 });
diff --git a/static/js/views/device-verify/device-verify.js b/static/js/views/device-verify/device-verify.js
index c62af2ab..8983f1ac 100644
--- a/static/js/views/device-verify/device-verify.js
+++ b/static/js/views/device-verify/device-verify.js
@@ -1,4 +1,6 @@
 // device-verify.js — Extracted from inline <script> in device-verify.html
+import { getCsrfHeaders } from '../../core/csrf.js';
+
 (() => {
     var API_BASE = window.location.origin;
     var codeInput = document.getElementById('user-code');
diff --git a/static/js/views/profile/profile.js b/static/js/views/profile/profile.js
index ebfdb6d3..fafee914 100644
--- a/static/js/views/profile/profile.js
+++ b/static/js/views/profile/profile.js
@@ -1,8 +1,11 @@
+import { getCsrfHeaders } from '../../core/csrf.js';
+import { i18n } from '../../core/i18n.js';
+
 const API = '/api';
 
 /* ── i18n helper — falls back to key if i18n not ready ── */
 function t(key, params) {
-    if (window.i18n && typeof window.i18n.t === 'function') return window.i18n.t(key, params);
+    if (i18n && typeof i18n.t === 'function') return i18n.t(key, params);
     return key.split('.').pop().replace(/_/g, ' ');
 }
 
diff --git a/static/js/views/shared/sharedView.js b/static/js/views/shared/sharedView.js
index 18475259..55ab6911 100644
--- a/static/js/views/shared/sharedView.js
+++ b/static/js/views/shared/sharedView.js
@@ -3,6 +3,13 @@
  * In-app shared files view. All operations go through the backend API.
  */
 
+import { switchToFilesSection } from '../../app/navigation.js';
+import { ui } from '../../app/ui.js';
+import { getCsrfHeaders } from '../../core/csrf.js';
+import { formatDateShort } from '../../core/formatters.js';
+import { i18n } from '../../core/i18n.js';
+import { fileSharing } from '../../features/sharing/fileSharing.js';
+
 const sharedView = {
     // State
     items: [],
@@ -181,8 +188,8 @@ const sharedView = {
             </div>
         `;
 
-        if (window.i18n?.translateElement) {
-            window.i18n.translateElement(container);
+        if (i18n?.translateElement) {
+            i18n.translateElement(container);
         }
     },
 
@@ -246,7 +253,7 @@ const sharedView = {
         const goToFilesBtn = document.getElementById('go-to-files-btn');
         if (goToFilesBtn) {
             goToFilesBtn.addEventListener('click', () => {
-                if (window.switchToFilesSection) window.switchToFilesSection();
+                if (switchToFilesSection) switchToFilesSection();
             });
         }
     },
@@ -590,8 +597,8 @@ const sharedView = {
             return;
         }
 
-        if (window.fileSharing?.sendShareNotification) {
-            window.fileSharing
+        if (fileSharing?.sendShareNotification) {
+            fileSharing
                 .sendShareNotification(this.currentItem.url, email, message)
                 .then(() => {
                     this.closeNotificationDialog();
@@ -602,8 +609,8 @@ const sharedView = {
     },
 
     showNotification(message, type = 'success') {
-        if (window.ui?.showNotification) {
-            window.ui.showNotification(message, type);
+        if (ui?.showNotification) {
+            ui.showNotification(message, type);
         } else {
             alert(message);
         }
@@ -614,13 +621,13 @@ const sharedView = {
     },
 
     formatDate(value) {
-        return window.formatDateShort ? window.formatDateShort(value) : String(value);
+        return formatDateShort(value);
     },
 
     translate(key, defaultText) {
-        if (window.i18n?.t) return window.i18n.t(key, defaultText);
+        if (i18n?.t) return i18n.t(key, defaultText);
         return defaultText;
     }
 };
 
-window.sharedView = sharedView;
+export { sharedView };
diff --git a/static/login.html b/static/login.html
index 7d8235d0..c7059df2 100644
--- a/static/login.html
+++ b/static/login.html
@@ -12,10 +12,7 @@
     <link rel="stylesheet" href="/css/views/auth.css">
 
     <!-- Scripts -->
-    <script src="/js/core/i18n.js"></script>
-    <script src="/js/core/csrf.js"></script>
-    <script src="/js/core/icons.js" defer></script>
-    <script src="/js/features/auth/auth.js" defer></script>
+    <script type="module" src="/js/features/auth/auth.js"></script>
 </head>
 <body>
     <div class="auth-container">
diff --git a/static/profile.html b/static/profile.html
index 01c80320..a8f42edb 100644
--- a/static/profile.html
+++ b/static/profile.html
@@ -5,9 +5,6 @@
 <meta name="viewport" content="width=device-width, initial-scale=1.0">
 <title>OxiCloud — My Profile</title>
 <script src="/js/core/theme-init.js"></script>
-<script src="/js/core/i18n.js" defer></script>
-<script src="/js/core/icons.js" defer></script>
-<script src="/js/core/csrf.js" defer></script>
 <link rel="stylesheet" href="/css/main.css">
 <link rel="stylesheet" href="/css/views/profile.css">
 </head>
@@ -164,6 +161,6 @@
   </div>
 </div>
 
-<script src="/js/views/profile/profile.js" defer></script>
+<script type="module" src="/js/views/profile/profile.js"></script>
 </body>
 </html>
diff --git a/static/sw.js b/static/sw.js
index ed5d41ce..d7053aab 100644
--- a/static/sw.js
+++ b/static/sw.js
@@ -1,12 +1,14 @@
 // OxiCloud Service Worker
-const CACHE_NAME = 'oxicloud-cache-v16';
+const CACHE_NAME = 'oxicloud-cache-v17';
+
+// Only cache static assets — NOT HTML files.
+// HTML files are served network-first so browsers always get the latest
+// script/link references. Caching HTML causes stale entry points.
 const ASSETS_TO_CACHE = [
-    '/',
-    '/index.html',
-    '/js/icons.js',
-    '/js/i18n.js',
-    '/js/languageSelector.js',
-    '/js/notifications.js',
+    '/js/core/icons.js',
+    '/js/core/i18n.js',
+    '/js/core/languageSelector.js',
+    '/js/core/notifications.js',
     '/locales/en.json',
     '/locales/es.json',
     '/locales/fa.json',
@@ -15,6 +17,9 @@ const ASSETS_TO_CACHE = [
     '/favicon.ico'
 ];
 
+// HTML paths that should always be fetched from the network
+const HTML_PATHS = ['/', '/index.html', '/login', '/login.html', '/admin', '/admin.html', '/profile', '/profile.html'];
+
 // Install event - cache assets
 self.addEventListener('install', (event) => {
     event.waitUntil(
@@ -55,6 +60,14 @@ self.addEventListener('fetch', (event) => {
         return;
     }
 
+    // HTML pages: always network-first so entry points are never stale
+    const pathname = new URL(event.request.url).pathname;
+    const isHtml = HTML_PATHS.includes(pathname) || pathname.endsWith('.html') || event.request.headers.get('accept')?.includes('text/html');
+    if (isHtml) {
+        event.respondWith(fetch(event.request).catch(() => caches.match(event.request)));
+        return;
+    }
+
     event.respondWith(
         caches.match(event.request).then((response) => {
             // Cache hit - return the response from the cached version