Fix sidebar icons visibility when collapsed

- Hide all menu icons when sidebar is collapsed
- Hide all menu text, header text, and footer content
- Create completely minimal collapsed state (60px wide)
- Only collapse button remains visible for expanding
- Smooth transitions for all elements
- Clean, distraction-free collapsed sidebar experience

When collapsed, sidebar now shows:
- Only the expand button (›)
- Clean gradient background
- 60px minimal width
- No icons or text bleeding through

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

styles.css

@@ -39,7 +39,10 @@ body {
 .sidebar.collapsed .menu-text,
 .sidebar.collapsed .sidebar-header h2,
 .sidebar.collapsed .user-info span,
-.sidebar.collapsed .logout-btn {
+.sidebar.collapsed .logout-btn,
+.sidebar.collapsed .sidebar-footer,
+.sidebar.collapsed .menu-icon,
+.sidebar.collapsed .sidebar-menu {
     opacity: 0;
     visibility: hidden;
     transition: opacity 0.2s ease, visibility 0.2s ease;
@@ -48,30 +51,16 @@ body {
 .menu-text,
 .sidebar-header h2,
 .user-info span,
-.logout-btn {
+.logout-btn,
+.menu-icon,
+.sidebar-menu {
     transition: opacity 0.2s ease, visibility 0.2s ease;
 }
 
-.sidebar.collapsed .menu-icon {
-    margin-right: 0;
-    text-align: center;
-    width: 100%;
-}
-
-.sidebar.collapsed .menu-item {
-    justify-content: center;
-    padding: 15px 0;
-}
-
 .sidebar.collapsed .sidebar-header {
     padding: 20px 10px;
 }
 
-.sidebar.collapsed .user-info {
-    padding: 15px 10px;
-    text-align: center;
-}
-
 .sidebar-header {
     padding: 30px 20px;
     border-bottom: 1px solid rgba(255, 255, 255, 0.1);