diff --git a/management/src/App.tsx b/management/src/App.tsx
index 8c9e344..c637889 100644
--- a/management/src/App.tsx
+++ b/management/src/App.tsx
@@ -125,7 +125,7 @@ function App() {
       try {
         const stored = localStorage.getItem('sc_my_classes_details');
         setMyClasses(stored ? JSON.parse(stored) : []);
-      } catch (e) {}
+      } catch (e) { }
     };
     window.addEventListener('my-classes-updated', handleUpdate);
     return () => window.removeEventListener('my-classes-updated', handleUpdate);
@@ -202,30 +202,6 @@ function App() {
             <span className="brand-name">Simple Care</span>
             <span className="brand-sub">Rikkei Education</span>
           </div>
-          <button
-            type="button"
-            className="sidebar-collapse-toggle-pc"
-            onClick={toggleSidebarCollapse}
-            title="Thu gọn menu"
-            style={{
-              background: 'none',
-              border: 'none',
-              color: 'var(--text-muted)',
-              cursor: 'pointer',
-              padding: '4px',
-              display: 'flex',
-              alignItems: 'center',
-              justifyContent: 'center',
-              marginLeft: 'auto',
-              borderRadius: '4px',
-              transition: 'var(--transition)',
-            }}
-          >
-            <svg viewBox="0 0 24 24" width="18" height="18" fill="none" stroke="currentColor" strokeWidth="2.5" strokeLinecap="round" strokeLinejoin="round">
-              <line x1="19" y1="12" x2="5" y2="12" />
-              <polyline points="12 19 5 12 12 5" />
-            </svg>
-          </button>
         </div>
 
         <nav>
@@ -365,37 +341,21 @@ function App() {
         </div>
       </aside>
 
+      <button
+        type="button"
+        className={`sidebar-edge-toggle${sidebarCollapsed ? ' sidebar-edge-toggle--collapsed' : ''}`}
+        onClick={toggleSidebarCollapse}
+        title={sidebarCollapsed ? 'Mở rộng menu' : 'Thu gọn menu'}
+      >
+        <svg viewBox="0 0 10 18" width="10" height="18" fill="currentColor">
+          {sidebarCollapsed
+            ? <path d="M1 1 L9 9 L1 17" />
+            : <path d="M9 1 L1 9 L9 17" />
+          }
+        </svg>
+      </button>
+
       <main className={`main-content${sidebarCollapsed ? ' main-content--full' : ''}`}>
-        {sidebarCollapsed && (
-          <button
-            type="button"
-            className="sidebar-expand-btn-pc"
-            onClick={toggleSidebarCollapse}
-            title="Mở rộng menu"
-            style={{
-              position: 'fixed',
-              left: '12px',
-              top: '12px',
-              zIndex: 99,
-              background: '#fff',
-              border: '1px solid var(--border-color)',
-              borderRadius: '50%',
-              width: '32px',
-              height: '32px',
-              display: 'flex',
-              alignItems: 'center',
-              justifyContent: 'center',
-              cursor: 'pointer',
-              boxShadow: 'var(--shadow-sm)',
-              transition: 'var(--transition)',
-            }}
-          >
-            <svg viewBox="0 0 24 24" width="16" height="16" fill="none" stroke="currentColor" strokeWidth="2.5" strokeLinecap="round" strokeLinejoin="round">
-              <line x1="5" y1="12" x2="19" y2="12" />
-              <polyline points="12 5 19 12 12 19" />
-            </svg>
-          </button>
-        )}
         <div className="page-viewport">
           {route.classId ? (
             <ClassWorkspace
diff --git a/management/src/index.css b/management/src/index.css
index ea017ee..3c5d068 100644
--- a/management/src/index.css
+++ b/management/src/index.css
@@ -95,13 +95,36 @@ body {
   pointer-events: none;
 }
 
-.sidebar-collapse-toggle-pc {
-  opacity: 0.5;
-  transition: opacity 0.15s;
+/* ── Sidebar Edge Toggle (triangle tab at mid-right edge) ── */
+.sidebar-edge-toggle {
+  position: fixed;
+  left: 272px;
+  top: 50%;
+  transform: translateY(-50%);
+  z-index: 11;
+  width: 16px;
+  height: 48px;
+  background: var(--bg-sidebar);
+  border: 1px solid var(--border-color);
+  border-left: none;
+  border-radius: 0 6px 6px 0;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  cursor: pointer;
+  color: var(--text-muted);
+  padding: 0;
+  transition: left 0.28s cubic-bezier(.4,0,.2,1), background 0.15s, color 0.15s;
+  box-shadow: 2px 0 6px rgba(0,0,0,0.06);
 }
-.sidebar-collapse-toggle-pc:hover {
-  opacity: 1;
-  color: var(--accent) !important;
+
+.sidebar-edge-toggle:hover {
+  background: var(--accent-light);
+  color: var(--accent);
+}
+
+.sidebar-edge-toggle--collapsed {
+  left: 0;
 }
 
 .sidebar > nav {
@@ -339,12 +362,6 @@ body {
   margin-left: 0;
 }
 
-.sidebar-expand-btn-pc:hover {
-  background: var(--accent-light) !important;
-  border-color: var(--accent) !important;
-  color: var(--accent) !important;
-}
-
 .page-viewport {
   flex: 1;
   min-height: 0;
@@ -4681,11 +4698,7 @@ input:checked + .slider:before {
     transform: translateX(0);
   }
 
-  .sidebar-collapse-toggle-pc {
-    display: none !important;
-  }
-
-  .sidebar-expand-btn-pc {
+  .sidebar-edge-toggle {
     display: none !important;
   }