diff --git a/OfflineU-project-summary.md b/OfflineU-project-summary.md
index 3fe3fca..919ccac 100644
--- a/OfflineU-project-summary.md
+++ b/OfflineU-project-summary.md
@@ -97,6 +97,32 @@ built locally from a private Gitea repo rather than pulling the upstream image.
   official palette (nordtheme.com). Anyone with `theme: "dainty"` already saved
   in `settings.json` falls back gracefully to the `dark` default on next load.
 
+## Mobile UI overhaul + in-app renaming (this session)
+- **Fixed the mobile text-overlap bug** — `.lesson-item`/`.tree-header` in
+  `course_dashboard.html` had no `min-width: 0` or truncation on their flex
+  children, so long course/lesson names (especially scene-release-style dotted
+  names like `Udemy.crash.course.electronics...Mimir` with zero whitespace to
+  wrap on) would overflow and visually overlap neighboring text on narrow
+  screens. Fixed with `min-width:0` + ellipsis truncation (desktop/tablet) and
+  a `@media (max-width: 600px)` block that stacks title/metadata into separate
+  lines with `overflow-wrap: break-word` (the dotted-name case needed this
+  specifically — plain `white-space: normal` doesn't create a break opportunity
+  in a string with no spaces).
+- **Library browser redesigned** — replaced the nested-indent accordion
+  (`AI` → `ChatGPT` → course, each level eating horizontal space) with a
+  single-level drill-down + breadcrumb (`Library / AI / ChatGPT`), the standard
+  mobile file-browser pattern. Tapping a folder now replaces the list instead
+  of nesting under it. In-course lesson tree keeps its old expand-in-place
+  behavior (shallower, wasn't the reported problem).
+- **Rename courses/folders from Settings** — "Curate Library" is now
+  "Manage Library": each row gets a ✏️ button alongside Hide/Show that renames
+  the directory in place on disk via a new `POST /api/rename-path`. Handles
+  path-traversal/collision validation, and rebases any `hidden_paths.json` /
+  `recent_views.json` entries nested under the renamed path (progress files
+  need no rebasing — they live inside the directory and are keyed relative to
+  it). If you rename your *currently loaded* course's folder, the app resets
+  to the library view rather than serving a stale path.
+
 ## Known limitations still open
 - App is unauthenticated by design (matches upstream) — settings and hidden-path
   curation apply app-wide, not per-browser/per-user.
diff --git a/offlineu_core.py b/offlineu_core.py
index 307db3f..d225f33 100644
--- a/offlineu_core.py
+++ b/offlineu_core.py
@@ -557,6 +557,48 @@ def set_path_hidden(path: str, hidden: bool) -> List[str]:
     return result
 
 
+def _rebase_prefix(value: str, old_abs: str, new_abs: str) -> str:
+    """If `value` equals or is nested under `old_abs`, rewrite that prefix to `new_abs`."""
+    if value == old_abs:
+        return new_abs
+    if value.startswith(old_abs + os.sep):
+        return new_abs + value[len(old_abs):]
+    return value
+
+
+def rebase_library_path(old_abs: str, new_abs: str) -> None:
+    """
+    After a directory in the library is renamed/moved on disk, rewrite any
+    stored absolute paths that pointed inside it (hidden_paths.json,
+    recent_views.json's course_path) so curation and Recently Viewed don't
+    silently go stale. Lesson-level progress needs no rebasing - it lives
+    inside the directory itself, keyed by paths relative to it, so it moves
+    with the rename automatically.
+    """
+    hidden = get_hidden_paths()
+    rebased_hidden = [_rebase_prefix(p, old_abs, new_abs) for p in hidden]
+    if rebased_hidden != hidden:
+        os.makedirs(DATA_DIR, exist_ok=True)
+        with open(HIDDEN_PATHS_FILE, 'w') as f:
+            json.dump(sorted(set(rebased_hidden)), f, indent=2)
+
+    views = get_recent_views()
+    changed = False
+    for entry in views:
+        course_path = entry.get('course_path', '')
+        rebased = _rebase_prefix(course_path, old_abs, new_abs)
+        if rebased != course_path:
+            entry['course_path'] = rebased
+            changed = True
+    if changed:
+        try:
+            os.makedirs(DATA_DIR, exist_ok=True)
+            with open(RECENT_VIEWS_FILE, 'w') as f:
+                json.dump(views, f, indent=2)
+        except OSError as e:
+            print(f"Could not rebase recent views after rename: {e}")
+
+
 def _contains_visible_course(directory: Path, hidden_set: set) -> bool:
     """
     Whether `directory` leads to at least one course that isn't curated
@@ -1037,6 +1079,54 @@ def set_hidden_path_api():
     return jsonify({'success': True, 'hidden_paths': updated})
 
 
+@app.route('/api/rename-path', methods=['POST'])
+def rename_path_api():
+    """Rename a course/folder directory in the library, in place on disk."""
+    global current_course
+
+    data = request.json or {}
+    path = data.get('path', '')
+    new_name = (data.get('new_name') or '').strip()
+
+    if not path:
+        return jsonify({'error': 'path is required'}), 400
+    if not new_name:
+        return jsonify({'error': 'New name cannot be empty'}), 400
+    if '/' in new_name or '\\' in new_name or '\x00' in new_name or new_name in ('.', '..'):
+        return jsonify({'error': 'New name cannot contain path separators'}), 400
+    if new_name.startswith('.'):
+        return jsonify({'error': 'New name cannot start with a dot'}), 400
+
+    library_root = os.path.abspath(get_library_root())
+    old_abs = os.path.abspath(path)
+    if not (old_abs == library_root or old_abs.startswith(library_root + os.sep)):
+        return jsonify({'error': 'Path outside library root'}), 403
+    if old_abs == library_root:
+        return jsonify({'error': 'Cannot rename the library root itself'}), 400
+    if not os.path.isdir(old_abs):
+        return jsonify({'error': 'Directory not found'}), 404
+
+    new_abs = os.path.join(os.path.dirname(old_abs), new_name)
+    if os.path.exists(new_abs):
+        return jsonify({'error': f'"{new_name}" already exists here'}), 409
+
+    try:
+        os.rename(old_abs, new_abs)
+    except OSError as e:
+        return jsonify({'error': f'Rename failed: {e}'}), 500
+
+    rebase_library_path(old_abs, new_abs)
+
+    active_course_reset = False
+    if current_course is not None:
+        course_abs = os.path.abspath(current_course.path)
+        if course_abs == old_abs or course_abs.startswith(old_abs + os.sep):
+            current_course = None
+            active_course_reset = True
+
+    return jsonify({'success': True, 'new_path': new_abs, 'active_course_reset': active_course_reset})
+
+
 @app.route('/settings')
 def settings_page():
     """Render the display-settings page."""
diff --git a/templates/course_dashboard.html b/templates/course_dashboard.html
index 8d5dd09..14717d6 100644
--- a/templates/course_dashboard.html
+++ b/templates/course_dashboard.html
@@ -248,6 +248,39 @@
             border-radius: 10px;
         }
 
+        .library-breadcrumb {
+            color: var(--text-muted);
+            font-size: 13px;
+            margin-top: 6px;
+            display: flex;
+            flex-wrap: wrap;
+            align-items: center;
+            gap: 4px;
+        }
+
+        .library-breadcrumb .crumb {
+            cursor: pointer;
+            max-width: 160px;
+            overflow: hidden;
+            text-overflow: ellipsis;
+            white-space: nowrap;
+        }
+
+        .library-breadcrumb .crumb:not(.current):hover {
+            color: var(--accent);
+            text-decoration: underline;
+        }
+
+        .library-breadcrumb .crumb.current {
+            color: var(--text-primary);
+            font-weight: 600;
+            cursor: default;
+        }
+
+        .library-breadcrumb .crumb-sep {
+            opacity: 0.5;
+        }
+
         /* Dynamic Directory Tree Styles */
         .tree-container {
             margin-top: 20px;
@@ -295,22 +328,31 @@
             align-items: center;
             gap: 10px;
             flex: 1;
+            min-width: 0;
         }
 
         .tree-icon {
             font-size: 1.2em;
             width: 20px;
             text-align: center;
+            flex-shrink: 0;
         }
 
         .tree-name {
             font-weight: 500;
+            flex: 1;
+            min-width: 0;
+            overflow: hidden;
+            text-overflow: ellipsis;
+            white-space: nowrap;
         }
 
         .tree-stats {
             font-size: 0.85em;
             color: var(--text-muted);
             margin-left: 10px;
+            flex-shrink: 0;
+            white-space: nowrap;
         }
 
         .tree-toggle {
@@ -405,10 +447,20 @@
             align-items: center;
             gap: 8px;
             flex: 1;
+            min-width: 0;
         }
 
         .lesson-icon {
             font-size: 1.1em;
+            flex-shrink: 0;
+        }
+
+        .lesson-name {
+            flex: 1;
+            min-width: 0;
+            overflow: hidden;
+            text-overflow: ellipsis;
+            white-space: nowrap;
         }
 
         .lesson-meta {
@@ -417,6 +469,16 @@
             display: flex;
             align-items: center;
             gap: 5px;
+            flex-shrink: 0;
+            min-width: 0;
+            max-width: 45%;
+        }
+
+        .lesson-meta-text {
+            overflow: hidden;
+            text-overflow: ellipsis;
+            white-space: nowrap;
+            min-width: 0;
         }
 
         .lesson-type {
@@ -473,6 +535,29 @@
                 margin-left: 15px;
             }
         }
+
+        @media (max-width: 600px) {
+            .lesson-item {
+                flex-direction: column;
+                align-items: flex-start;
+                gap: 6px;
+            }
+
+            .lesson-title,
+            .lesson-meta {
+                width: 100%;
+                max-width: 100%;
+            }
+
+            .lesson-name,
+            .lesson-meta-text {
+                overflow: visible;
+                text-overflow: clip;
+                white-space: normal;
+                overflow-wrap: break-word;
+                word-break: break-word;
+            }
+        }
     </style>
 </head>
 <body>
@@ -563,7 +648,7 @@
                                     {% elif lesson.lesson_type == 'mixed' %}📦
                                     {% else %}📄{% endif %}
                                 </span>
-                                {{ lesson.title }}
+                                <span class="lesson-name">{{ lesson.title }}</span>
                             </div>
                             <div class="lesson-meta">
                                 <span class="lesson-type {{ lesson.lesson_type }}">{{ lesson.lesson_type|title }}</span>
@@ -599,7 +684,7 @@
                          onclick="window.location.href='/recent/open?course_path={{ view.course_path | urlencode }}&lesson_path={{ view.lesson_path | urlencode }}'">
                         <div class="lesson-title">
                             <span class="lesson-icon">▶️</span>
-                            <span>{{ view.lesson_title }}</span>
+                            <span class="lesson-name">{{ view.lesson_title }}</span>
                         </div>
                         <div class="lesson-meta">
                             {% if view.completed %}
@@ -607,7 +692,7 @@
                             {% elif view.percent_watched %}
                             <span class="watched-badge">{{ view.percent_watched }}% watched</span>
                             {% endif %}
-                            <span>{{ view.course_name }}{% if view.viewed_display %} · {{ view.viewed_display }}{% endif %}</span>
+                            <span class="lesson-meta-text">{{ view.course_name }}{% if view.viewed_display %} · {{ view.viewed_display }}{% endif %}</span>
                         </div>
                         {% if view.percent_watched %}
                         <div class="lesson-progress-track"><div class="lesson-progress-fill" style="width: {{ view.percent_watched }}%;"></div></div>
@@ -621,7 +706,7 @@
         <div class="container">
             <div class="card" id="library-card">
                 <h2>Your Courses</h2>
-                <p id="library-path-bar" style="color: #999; font-size: 13px; margin-top: 6px;"></p>
+                <p id="library-path-bar" class="library-breadcrumb"></p>
                 <div id="library-groups" style="margin-top: 15px;"></div>
             </div>
         </div>
@@ -665,22 +750,29 @@
             }
         }
 
+        // Single-level drill-down: the Library browser shows one folder's
+        // contents at a time (replacing the list, not nesting under it) and
+        // tracks how we got here in libraryTrail so a breadcrumb can jump
+        // back up. Much less horizontal space wasted than the old
+        // indent-per-level accordion, especially on narrow screens.
+        let libraryTrail = []; // [{name, path}], root is implicit (not in the array)
+
         function loadLibrary() {
             const libraryCard = document.getElementById('library-card');
             if (!libraryCard) return;
-            fetchLibraryLevel(null, document.getElementById('library-groups'), true);
+            libraryTrail = [];
+            fetchLibraryLevel(null);
         }
 
-        function fetchLibraryLevel(path, container, isRoot) {
+        function fetchLibraryLevel(path) {
+            const container = document.getElementById('library-groups');
+            container.innerHTML = '<p style="color:#999; padding: 6px 0;">Loading...</p>';
             const url = path ? `/library?path=${encodeURIComponent(path)}` : '/library';
             fetch(url)
                 .then(r => r.json())
                 .then(data => {
-                    if (isRoot) {
-                        document.getElementById('library-path-bar').textContent =
-                            `Scanning ${data.library_path}`;
-                    }
-                    renderLibraryLevel(data, container, isRoot);
+                    renderLibraryBreadcrumb();
+                    renderLibraryLevel(data);
                 })
                 .catch(() => {
                     container.innerHTML =
@@ -688,7 +780,35 @@
                 });
         }
 
-        function renderLibraryLevel(data, container, isRoot) {
+        function renderLibraryBreadcrumb() {
+            const bar = document.getElementById('library-path-bar');
+            const atRoot = libraryTrail.length === 0;
+            let html = `<span class="crumb ${atRoot ? 'current' : ''}"` +
+                (atRoot ? '' : ` onclick="goToLibraryCrumb(-1)"`) + `>Library</span>`;
+            libraryTrail.forEach((crumb, i) => {
+                const isLast = i === libraryTrail.length - 1;
+                html += ` <span class="crumb-sep">/</span> ` +
+                    `<span class="crumb ${isLast ? 'current' : ''}"` +
+                    (isLast ? '' : ` onclick="goToLibraryCrumb(${i})"`) +
+                    `>${crumb.name}</span>`;
+            });
+            bar.innerHTML = html;
+        }
+
+        function goToLibraryCrumb(index) {
+            if (index < 0) {
+                libraryTrail = [];
+                fetchLibraryLevel(null);
+                return;
+            }
+            const target = libraryTrail[index];
+            libraryTrail = libraryTrail.slice(0, index + 1);
+            fetchLibraryLevel(target.path);
+        }
+
+        function renderLibraryLevel(data) {
+            const container = document.getElementById('library-groups');
+            const isRoot = libraryTrail.length === 0;
             if (!data.items || data.items.length === 0) {
                 const reason = (data.errors && data.errors.length)
                     ? data.errors.join(' ')
@@ -698,52 +818,35 @@
             }
 
             container.innerHTML = data.items.map(item => {
+                const safePath = item.path.replace(/'/g, "\\'");
                 if (item.type === 'course') {
                     return `
                         <div class="lesson-item"
-                             onclick="loadCoursePath('${item.path.replace(/'/g, "\\'")}')">
+                             onclick="loadCoursePath('${safePath}')">
                             <div class="lesson-title">
                                 <span class="lesson-icon">🎓</span>
-                                <span>${item.name}</span>
+                                <span class="lesson-name">${item.name}</span>
                             </div>
                             <span class="lesson-meta">${item.media_files} media file${item.media_files === 1 ? '' : 's'}</span>
                         </div>
                     `;
                 }
+                const safeName = item.name.replace(/'/g, "\\'");
                 return `
-                    <div class="tree-item">
-                        <div class="tree-header directory" onclick="toggleLibraryDir(this, '${item.path.replace(/'/g, "\\'")}')">
-                            <div class="tree-title">
-                                <span class="tree-icon">📁</span>
-                                <span class="tree-name">${item.name}</span>
-                            </div>
-                            <button class="tree-toggle">▶</button>
+                    <div class="tree-header directory" onclick="enterLibraryDir('${safePath}', '${safeName}')">
+                        <div class="tree-title">
+                            <span class="tree-icon">📁</span>
+                            <span class="tree-name">${item.name}</span>
                         </div>
-                        <div class="tree-content" data-loaded="false"></div>
+                        <span class="tree-toggle">›</span>
                     </div>
                 `;
             }).join('');
         }
 
-        function toggleLibraryDir(headerEl, path) {
-            const content = headerEl.nextElementSibling;
-            const toggle = headerEl.querySelector('.tree-toggle');
-            if (!content || !content.classList.contains('tree-content')) return;
-
-            if (content.classList.contains('expanded')) {
-                content.classList.remove('expanded');
-                toggle.textContent = '▶';
-                return;
-            }
-
-            content.classList.add('expanded');
-            toggle.textContent = '▼';
-
-            if (content.dataset.loaded === 'true') return; // already fetched this branch
-
-            content.innerHTML = '<p style="color:#999; padding: 6px 0;">Loading...</p>';
-            content.dataset.loaded = 'true';
-            fetchLibraryLevel(path, content, false);
+        function enterLibraryDir(path, name) {
+            libraryTrail.push({ name: name, path: path });
+            fetchLibraryLevel(path);
         }
 
         function loadCoursePath(path) {
diff --git a/templates/settings.html b/templates/settings.html
index 5b9c773..373d170 100644
--- a/templates/settings.html
+++ b/templates/settings.html
@@ -209,6 +209,7 @@
         }
         .curate-row {
             display: flex;
+            flex-wrap: wrap;
             align-items: center;
             justify-content: space-between;
             gap: 10px;
@@ -255,6 +256,28 @@
             font-size: 0.9em;
             padding: 6px 0;
         }
+        .curate-actions {
+            display: flex;
+            align-items: center;
+            gap: 6px;
+            flex-shrink: 0;
+        }
+        .curate-rename-input {
+            flex: 1;
+            min-width: 0;
+            background: var(--bg-primary);
+            color: var(--text-primary);
+            border: 1px solid var(--accent);
+            border-radius: var(--radius);
+            padding: 4px 8px;
+            font-size: 0.95em;
+            font-family: var(--font-family);
+        }
+        .curate-row-status {
+            flex-basis: 100%;
+            font-size: 0.8em;
+            color: #ff6b6b;
+        }
         #save-status {
             font-size: 0.9em;
             color: #28a745;
@@ -384,10 +407,11 @@
         </div>
 
         <div class="card">
-            <h2>Curate Library</h2>
+            <h2>Manage Library</h2>
             <p class="setting-desc" style="margin-bottom: 12px;">
-                Hide courses or whole folders from the Library browser without touching anything on disk.
-                Hiding a folder hides everything inside it.
+                Hide courses or whole folders from the Library browser without touching anything on disk
+                (hiding a folder hides everything inside it), or rename a course/folder directly - no need
+                to go to the NAS.
             </p>
 
             <div id="hidden-list-wrap" style="margin-bottom: 15px; display: none;">
@@ -395,7 +419,7 @@
                 <div id="hidden-list"></div>
             </div>
 
-            <div style="font-weight: 600; margin-bottom: 8px; font-size: 0.9em; color: var(--text-muted);">Browse to hide</div>
+            <div style="font-weight: 600; margin-bottom: 8px; font-size: 0.9em; color: var(--text-muted);">Browse</div>
             <div id="curate-path-bar" style="color: var(--text-muted); font-size: 13px; margin-bottom: 8px;"></div>
             <div id="curate-tree"></div>
         </div>
@@ -549,9 +573,12 @@
             }
             container.innerHTML = data.items.map(item => {
                 const safePath = item.path.replace(/'/g, "\\'");
+                const safeName = item.name.replace(/'/g, "\\'");
                 const icon = item.type === 'course' ? '🎓' : '📁';
                 const hiddenClass = item.hidden ? 'is-hidden' : '';
+                const renameBtn = `<button class="btn btn-secondary btn-sm" onclick="event.stopPropagation(); startRename(this, '${safePath}', '${safeName}')" title="Rename">✏️</button>`;
                 const toggleBtn = `<button class="btn btn-secondary btn-sm" onclick="event.stopPropagation(); toggleHidden('${safePath}', ${!item.hidden}, this)">${item.hidden ? 'Show' : 'Hide'}</button>`;
+                const actions = `<div class="curate-actions">${renameBtn}${toggleBtn}</div>`;
 
                 if (item.type === 'course') {
                     return `
@@ -560,7 +587,7 @@
                                 <span>${icon}</span>
                                 <span class="name">${item.name}</span>
                             </div>
-                            ${toggleBtn}
+                            ${actions}
                         </div>
                     `;
                 }
@@ -571,7 +598,7 @@
                             <span>${icon}</span>
                             <span class="name">${item.name}</span>
                         </div>
-                        ${toggleBtn}
+                        ${actions}
                     </div>
                     <div class="curate-children" data-loaded="false"></div>
                 `;
@@ -620,6 +647,83 @@
             .catch(() => {});
         }
 
+        // ---- Library curation: rename a course/folder in place on disk ----
+        function startRename(btnEl, path, currentName) {
+            const row = btnEl.closest('.curate-row');
+            const nameSpan = row ? row.querySelector('.curate-row-name .name') : null;
+            if (!row || !nameSpan) return;
+
+            let settled = false;
+            const input = document.createElement('input');
+            input.type = 'text';
+            input.className = 'curate-rename-input';
+            input.value = currentName;
+            input.onclick = (e) => e.stopPropagation();
+            nameSpan.replaceWith(input);
+            input.focus();
+            input.select();
+
+            function cancel() {
+                if (settled) return;
+                settled = true;
+                input.replaceWith(nameSpan);
+            }
+            function commit() {
+                if (settled) return;
+                const newName = input.value.trim();
+                if (!newName || newName === currentName) {
+                    cancel();
+                    return;
+                }
+                settled = true;
+                submitRename(btnEl, path, newName, row, nameSpan, input);
+            }
+            input.addEventListener('keydown', (e) => {
+                e.stopPropagation();
+                if (e.key === 'Enter') { e.preventDefault(); commit(); }
+                else if (e.key === 'Escape') { e.preventDefault(); cancel(); }
+            });
+            input.addEventListener('blur', commit);
+        }
+
+        function submitRename(btnEl, path, newName, row, nameSpan, input) {
+            fetch('/api/rename-path', {
+                method: 'POST',
+                headers: { 'Content-Type': 'application/json' },
+                body: JSON.stringify({ path: path, new_name: newName })
+            })
+            .then(r => r.json().then(data => ({ ok: r.ok, data })))
+            .then(({ ok, data }) => {
+                if (!ok || !data.success) {
+                    input.replaceWith(nameSpan); // nameSpan still shows the original, unchanged name
+                    showRowError(row, data.error || 'Rename failed');
+                    return;
+                }
+                if (data.active_course_reset) {
+                    alert('That was your active course - reload the main page to pick it up under its new name.');
+                }
+                loadHiddenList();
+                const container = btnEl.closest('.curate-children') || document.getElementById('curate-tree');
+                const isRootContainer = container.id === 'curate-tree';
+                const refreshPath = isRootContainer ? null : container.dataset.path;
+                loadCurateLevel(refreshPath, container, isRootContainer);
+            })
+            .catch(() => {
+                input.replaceWith(nameSpan);
+                showRowError(row, 'Could not reach the server');
+            });
+        }
+
+        function showRowError(row, message) {
+            let status = row.querySelector('.curate-row-status');
+            if (!status) {
+                status = document.createElement('div');
+                status.className = 'curate-row-status';
+                row.appendChild(status);
+            }
+            status.textContent = message;
+        }
+
         loadHiddenList();
         loadCurateLevel(null, document.getElementById('curate-tree'), true);