feat: добавлена светлая тема с кнопкой переключения

frontend/student/index.html

@@ -13,14 +13,37 @@
             box-sizing: border-box;
         }
 
+        :root {
+            --bg-primary: #0f0f1a;
+            --text-primary: #f0f0f5;
+            --text-secondary: #9ca3af;
+            --accent-hover: #818cf8;
+            --bg-card: rgba(255, 255, 255, 0.05);
+            --bg-card-border: rgba(255, 255, 255, 0.08);
+            --bg-input: rgba(255, 255, 255, 0.06);
+            --accent-glow: rgba(99, 102, 241, 0.35);
+        }
+
+        [data-theme="light"] {
+            --bg-primary: #e8eaef;
+            --text-primary: #0f172a;
+            --text-secondary: #374151;
+            --accent-hover: #4f46e5;
+            --bg-card: rgba(255, 255, 255, 0.95);
+            --bg-card-border: rgba(0, 0, 0, 0.22);
+            --bg-input: rgba(0, 0, 0, 0.08);
+            --accent-glow: rgba(99, 102, 241, 0.25);
+        }
+
         body {
             font-family: 'Inter', sans-serif;
-            background: #0f0f1a;
-            color: #f0f0f5;
+            background: var(--bg-primary);
+            color: var(--text-primary);
             min-height: 100vh;
             display: flex;
             align-items: center;
             justify-content: center;
+            transition: background 0.4s ease, color 0.4s ease;
         }
 
         .placeholder {
@@ -33,18 +56,57 @@
         }
 
         .placeholder p {
-            color: #9ca3af;
+            color: var(--text-secondary);
             margin-bottom: 1.5rem;
         }
 
         .placeholder a {
-            color: #818cf8;
+            color: var(--accent-hover);
             text-decoration: none;
         }
 
         .placeholder a:hover {
             text-decoration: underline;
         }
+
+        /* Theme Toggle */
+        .theme-toggle {
+            width: 42px;
+            height: 42px;
+            border-radius: 50%;
+            background: var(--bg-card);
+            border: 1px solid var(--bg-card-border);
+            color: var(--text-primary);
+            cursor: pointer;
+            display: flex;
+            align-items: center;
+            justify-content: center;
+            backdrop-filter: blur(12px);
+            -webkit-backdrop-filter: blur(12px);
+            transition: background 0.3s ease, transform 0.3s ease, box-shadow 0.3s ease;
+            z-index: 100;
+        }
+
+        .theme-toggle svg {
+            width: 20px;
+            height: 20px;
+            transition: transform 0.4s ease;
+        }
+
+        .theme-toggle:hover {
+            transform: scale(1.1);
+            box-shadow: 0 4px 16px var(--accent-glow);
+        }
+
+        .theme-toggle:active {
+            transform: scale(0.95);
+        }
+
+        .theme-toggle--fixed {
+            position: fixed;
+            top: 1.25rem;
+            right: 1.25rem;
+        }
     </style>
 </head>
 
@@ -52,8 +114,10 @@
     <div class="placeholder">
         <h1>Панель студента</h1>
         <p>Раздел в разработке</p>
-        <a href="/" onclick="localStorage.clear()">Выйти</a>
+        <a href="/" onclick="localStorage.removeItem('token'); localStorage.removeItem('role')">Выйти</a>
     </div>
+
+    <script src="/theme-toggle.js"></script>
 </body>
 
 </html>