fix

management/src/App.tsx

@@ -107,11 +107,15 @@ function App() {
   });
 
   const toggleSidebarCollapse = () => {
+    // On mobile (<=900px), just close the sidebar overlay
+    if (window.innerWidth <= 900) {
+      setSidebarOpen(false);
+      return;
+    }
+    // On desktop, toggle collapsed state
     const nextVal = !sidebarCollapsed;
     setSidebarCollapsed(nextVal);
     localStorage.setItem('sc_sidebar_collapsed', String(nextVal));
-    // On mobile, also close sidebar overlay when collapsing
-    if (nextVal) setSidebarOpen(false);
   };
   const [myClasses, setMyClasses] = useState<{ id: number; name: string; code: string }[]>(() => {
     try {