now responsive for mobile

frontend/style.css

@@ -344,3 +344,59 @@ tr[draggable="true"]:active { cursor: grabbing; }
     flex-direction: column;
     gap: 0.25rem;
 }
+
+/* Hamburger menu button — hidden on desktop */
+.hamburger {
+    display: none;
+    position: fixed;
+    top: 0.75rem;
+    left: 0.75rem;
+    z-index: 101;
+    background: var(--bg-secondary);
+    border: 1px solid var(--border);
+    border-radius: var(--radius);
+    color: var(--text-primary);
+    font-size: 1.4rem;
+    padding: 0.25rem 0.6rem;
+    cursor: pointer;
+    line-height: 1;
+}
+
+/* Sidebar overlay — hidden on desktop */
+.sidebar-overlay {
+    display: none;
+    position: fixed;
+    inset: 0;
+    background: rgba(0, 0, 0, 0.5);
+    z-index: 99;
+}
+
+/* Mobile responsive */
+@media (max-width: 768px) {
+    .hamburger { display: block; }
+    .sidebar-overlay.open { display: block; }
+    .sidebar {
+        transform: translateX(-100%);
+        z-index: 100;
+        transition: transform 0.2s ease;
+    }
+    .sidebar.open { transform: translateX(0); }
+    .main-content {
+        margin-left: 0;
+        padding: 1rem;
+        padding-top: 3.5rem;
+    }
+    .stats-grid { grid-template-columns: repeat(2, 1fr); }
+    table { display: block; overflow-x: auto; }
+    .form-group input[type="text"],
+    .form-group input[type="number"],
+    .form-group input[type="password"],
+    .form-group select {
+        width: 100% !important;
+        min-width: 0 !important;
+    }
+    .tab-bar { overflow-x: auto; }
+    .album-art-lg { width: 120px; height: 120px; }
+    .album-header { flex-direction: column; }
+    .artist-photo { width: 80px; height: 80px; }
+}