Feature Verification:

• ✅ Supports infinite nested menus
• ✅ Clicking menu items won't collapse already expanded submenus
• 🔄 When clicking different submenus, the previous submenu automatically collapses (unique-opened)
• ✅ After expanding a submenu and clicking its menu items, the submenu remains expanded
• ✅ Third and fourth level menus display and interact normally
• ✅ Floating layer menus display correctly in collapsed state
• ✅ Menu active state displays correctly
• ✅ Menu expansion state persists after refresh
• ✅ Active menu state persists after refresh