refactor: update class names for consistency and improve styling

- Changed `flex-shrink-0` to `shrink-0` in multiple components for better consistency.
- Updated button and checkbox classes to use `rounded-sm` for a more uniform appearance.
- Adjusted backdrop blur classes for modals to `backdrop-blur-xs` for a subtler effect.
- Removed unused Tailwind CSS configuration file.

src/components/NotificationBell.jsx

@@ -148,7 +148,7 @@ export default function NotificationBell() {
                       ${n.read ? 'hover:bg-th-hover' : 'bg-th-accent/5 hover:bg-th-accent/10'}`}
                   >
                     {/* Icon */}
-                    <span className="text-lg flex-shrink-0 mt-0.5">{notificationIcon(n.type)}</span>
+                    <span className="text-lg shrink-0 mt-0.5">{notificationIcon(n.type)}</span>
 
                     {/* Content */}
                     <div className="flex-1 min-w-0">
@@ -164,7 +164,7 @@ export default function NotificationBell() {
                     </div>
 
                     {/* Right side: unread dot, link icon, delete button */}
-                    <div className="flex flex-col items-end gap-1 flex-shrink-0">
+                    <div className="flex flex-col items-end gap-1 shrink-0">
                       {!n.read && (
                         <span className="w-2 h-2 rounded-full bg-th-accent mt-1" />
                       )}
@@ -173,7 +173,7 @@ export default function NotificationBell() {
                       )}
                       <button
                         onClick={(e) => handleDelete(e, n.id)}
-                        className="opacity-0 group-hover:opacity-100 p-0.5 rounded hover:text-th-error transition-all text-th-text-s/50"
+                        className="opacity-0 group-hover:opacity-100 p-0.5 rounded-sm hover:text-th-error transition-all text-th-text-s/50"
                         title={t('notifications.delete')}
                       >
                         <X size={13} />