diff --git a/frontend/admin/admin.css b/frontend/admin/admin.css
index 7b6498b..76d3749 100644
--- a/frontend/admin/admin.css
+++ b/frontend/admin/admin.css
@@ -29,6 +29,46 @@
     --transition: 0.2s ease;
 }
 
+/* ===== Light Theme ===== */
+[data-theme="light"] {
+    --bg-primary: #e8eaef;
+    --bg-sidebar: rgba(255, 255, 255, 0.88);
+    --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);
+    --bg-input-focus: rgba(0, 0, 0, 0.12);
+    --bg-hover: rgba(0, 0, 0, 0.08);
+    --text-primary: #0f172a;
+    --text-secondary: #374151;
+    --text-placeholder: #6b7280;
+    --accent: #6366f1;
+    --accent-hover: #4f46e5;
+    --accent-glow: rgba(99, 102, 241, 0.25);
+    --error: #dc2626;
+    --success: #16a34a;
+    --warning: #d97706;
+}
+
+[data-theme="light"] .form-group select option,
+[data-theme="light"] .filter-row select option {
+    background: #fff;
+    color: #1a1a2e;
+}
+
+[data-theme="light"] .nav-item.active {
+    background: rgba(99, 102, 241, 0.18);
+}
+
+[data-theme="light"] .form-group input,
+[data-theme="light"] .form-group select,
+[data-theme="light"] .filter-row select {
+    border-color: rgba(0, 0, 0, 0.15);
+}
+
+[data-theme="light"] tbody td {
+    border-bottom-color: rgba(0, 0, 0, 0.08);
+}
+
 html {
     font-size: 16px;
     -webkit-font-smoothing: antialiased;
@@ -40,6 +80,7 @@ body {
     color: var(--text-primary);
     min-height: 100vh;
     display: flex;
+    transition: background 0.4s ease, color 0.4s ease;
 }
 
 /* ===== Sidebar ===== */
@@ -55,6 +96,7 @@ body {
     top: 0;
     bottom: 0;
     z-index: 10;
+    transition: background 0.4s ease, border-color 0.4s ease;
 }
 
 .sidebar-header {
@@ -135,12 +177,18 @@ body {
 .topbar {
     padding: 1.5rem 2rem;
     border-bottom: 1px solid var(--bg-card-border);
+    transition: border-color 0.4s ease;
+    display: flex;
+    align-items: center;
+    justify-content: space-between;
+    gap: 1rem;
 }
 
 .topbar h1 {
     font-size: 1.3rem;
     font-weight: 700;
     letter-spacing: -0.02em;
+    flex: 1;
 }
 
 .content {
@@ -156,16 +204,16 @@ body {
     border: 1px solid var(--bg-card-border);
     border-radius: var(--radius-md);
     padding: 1.5rem;
+    transition: background 0.4s ease, border-color 0.4s ease;
 }
 
 .card h2 {
-    font-size: 1rem;
+    font-size: 0.8rem;
     font-weight: 600;
     margin-bottom: 1rem;
     color: var(--text-secondary);
     text-transform: uppercase;
     letter-spacing: 0.04em;
-    font-size: 0.8rem;
 }
 
 /* ===== Create Form ===== */
@@ -462,6 +510,44 @@ tbody tr:hover {
     backdrop-filter: blur(2px);
 }
 
+/* ===== Theme Toggle Button ===== */
+.theme-toggle {
+    width: 38px;
+    height: 38px;
+    border-radius: 50%;
+    background: var(--bg-input);
+    border: 1px solid var(--bg-card-border);
+    color: var(--text-primary);
+    cursor: pointer;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    transition: background 0.3s ease, transform 0.3s ease, box-shadow 0.3s ease;
+    flex-shrink: 0;
+}
+
+.theme-toggle svg {
+    width: 18px;
+    height: 18px;
+    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;
+    z-index: 100;
+}
+
 /* ===== Responsive ===== */
 @media (max-width: 768px) {
     .sidebar {
diff --git a/frontend/admin/index.html b/frontend/admin/index.html
index 19fdeae..1fa9ac6 100644
--- a/frontend/admin/index.html
+++ b/frontend/admin/index.html
@@ -227,6 +227,7 @@
         </section>
     </main>
 
+    <script src="/theme-toggle.js"></script>
     <script src="admin.js"></script>
 </body>
 
diff --git a/frontend/index.html b/frontend/index.html
index 025cc5e..65a4acf 100644
--- a/frontend/index.html
+++ b/frontend/index.html
@@ -81,6 +81,7 @@
     </div>
   </main>
 
+  <script src="theme-toggle.js"></script>
   <script src="script.js"></script>
 </body>
 </html>
diff --git a/frontend/student/index.html b/frontend/student/index.html
index 34f0a27..2a04092 100644
--- a/frontend/student/index.html
+++ b/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>
\ No newline at end of file
diff --git a/frontend/style.css b/frontend/style.css
index a1aecf7..a995c66 100644
--- a/frontend/style.css
+++ b/frontend/style.css
@@ -27,6 +27,33 @@
   --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
 }
 
+/* ===== Light Theme ===== */
+[data-theme="light"] {
+  --bg-primary: #e8eaef;
+  --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);
+  --bg-input-focus: rgba(0, 0, 0, 0.12);
+  --text-primary: #0f172a;
+  --text-secondary: #374151;
+  --text-placeholder: #6b7280;
+  --accent: #6366f1;
+  --accent-hover: #4f46e5;
+  --accent-glow: rgba(99, 102, 241, 0.25);
+  --error: #dc2626;
+  --success: #16a34a;
+}
+
+[data-theme="light"] .shape {
+  opacity: 0.25;
+}
+
+[data-theme="light"] .login-card {
+  box-shadow:
+    0 8px 32px rgba(0, 0, 0, 0.08),
+    inset 0 1px 0 rgba(255, 255, 255, 0.6);
+}
+
 html {
   font-size: 16px;
   -webkit-font-smoothing: antialiased;
@@ -42,6 +69,7 @@ body {
   align-items: center;
   justify-content: center;
   overflow: hidden;
+  transition: background 0.4s ease, color 0.4s ease;
 }
 
 /* ===== Animated Background ===== */
@@ -58,6 +86,7 @@ body {
   filter: blur(80px);
   opacity: 0.5;
   animation: float 20s ease-in-out infinite;
+  transition: opacity 0.4s ease;
 }
 
 .shape-1 {
@@ -89,10 +118,23 @@ body {
 }
 
 @keyframes float {
-  0%, 100% { transform: translate(0, 0) scale(1); }
-  25% { transform: translate(30px, -40px) scale(1.05); }
-  50% { transform: translate(-20px, 20px) scale(0.95); }
-  75% { transform: translate(15px, 35px) scale(1.03); }
+
+  0%,
+  100% {
+    transform: translate(0, 0) scale(1);
+  }
+
+  25% {
+    transform: translate(30px, -40px) scale(1.05);
+  }
+
+  50% {
+    transform: translate(-20px, 20px) scale(0.95);
+  }
+
+  75% {
+    transform: translate(15px, 35px) scale(1.03);
+  }
 }
 
 /* ===== Login Container ===== */
@@ -110,6 +152,7 @@ body {
     opacity: 0;
     transform: translateY(24px);
   }
+
   to {
     opacity: 1;
     transform: translateY(0);
@@ -127,6 +170,7 @@ body {
   box-shadow:
     0 8px 32px rgba(0, 0, 0, 0.3),
     inset 0 1px 0 rgba(255, 255, 255, 0.05);
+  transition: background 0.4s ease, border-color 0.4s ease, box-shadow 0.4s ease;
 }
 
 /* ===== Header ===== */
@@ -142,8 +186,15 @@ body {
 }
 
 @keyframes pulse-glow {
-  0%, 100% { filter: drop-shadow(0 0 6px var(--accent-glow)); }
-  50% { filter: drop-shadow(0 0 18px var(--accent-glow)); }
+
+  0%,
+  100% {
+    filter: drop-shadow(0 0 6px var(--accent-glow));
+  }
+
+  50% {
+    filter: drop-shadow(0 0 18px var(--accent-glow));
+  }
 }
 
 .login-header h1 {
@@ -214,8 +265,8 @@ body {
   box-shadow: 0 0 0 3px var(--accent-glow);
 }
 
-.input-wrapper input:focus ~ .input-icon,
-.input-wrapper input:focus + .input-icon {
+.input-wrapper input:focus~.input-icon,
+.input-wrapper input:focus+.input-icon {
   color: var(--accent);
 }
 
@@ -320,7 +371,9 @@ body {
 }
 
 @keyframes spin {
-  to { transform: rotate(360deg); }
+  to {
+    transform: rotate(360deg);
+  }
 }
 
 /* ===== Input Error State ===== */
@@ -329,6 +382,47 @@ body {
   box-shadow: 0 0 0 3px rgba(248, 113, 113, 0.15);
 }
 
+/* ===== Theme Toggle Button ===== */
+.theme-toggle {
+  width: 42px;
+  height: 42px;
+  border: none;
+  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;
+  flex-shrink: 0;
+}
+
+.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;
+}
+
 /* ===== Responsive ===== */
 @media (max-width: 480px) {
   .login-card {
@@ -338,4 +432,16 @@ body {
   .login-header h1 {
     font-size: 1.3rem;
   }
-}
+
+  .theme-toggle--fixed {
+    top: 0.75rem;
+    right: 0.75rem;
+    width: 36px;
+    height: 36px;
+  }
+
+  .theme-toggle--fixed svg {
+    width: 18px;
+    height: 18px;
+  }
+}
\ No newline at end of file
diff --git a/frontend/teacher/index.html b/frontend/teacher/index.html
index 718bfae..f3d04af 100644
--- a/frontend/teacher/index.html
+++ b/frontend/teacher/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 преподавателя</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>
\ No newline at end of file
diff --git a/frontend/theme-toggle.js b/frontend/theme-toggle.js
new file mode 100644
index 0000000..2931635
--- /dev/null
+++ b/frontend/theme-toggle.js
@@ -0,0 +1,65 @@
+/**
+ * Theme Toggle — shared across all pages.
+ * Reads/writes 'theme' key in localStorage.
+ * Injects an animated moon/sun button into the page.
+ */
+(() => {
+  'use strict';
+
+  const STORAGE_KEY = 'theme';
+
+  /* ---------- SVG icons ---------- */
+  const moonSVG = `<svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M21 12.79A9 9 0 1 1 11.21 3a7 7 0 0 0 9.79 9.79z"/></svg>`;
+  const sunSVG = `<svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><circle cx="12" cy="12" r="5"/><line x1="12" y1="1" x2="12" y2="3"/><line x1="12" y1="21" x2="12" y2="23"/><line x1="4.22" y1="4.22" x2="5.64" y2="5.64"/><line x1="18.36" y1="18.36" x2="19.78" y2="19.78"/><line x1="1" y1="12" x2="3" y2="12"/><line x1="21" y1="12" x2="23" y2="12"/><line x1="4.22" y1="19.78" x2="5.64" y2="18.36"/><line x1="18.36" y1="5.64" x2="19.78" y2="4.22"/></svg>`;
+
+  /* ---------- Apply saved theme BEFORE paint ---------- */
+  const saved = localStorage.getItem(STORAGE_KEY);
+  if (saved) {
+    document.documentElement.setAttribute('data-theme', saved);
+  }
+
+  /* ---------- Create button when DOM ready ---------- */
+  function init() {
+    const isDark = () => document.documentElement.getAttribute('data-theme') !== 'light';
+
+    const btn = document.createElement('button');
+    btn.className = 'theme-toggle';
+    btn.setAttribute('aria-label', 'Переключить тему');
+    btn.innerHTML = isDark() ? moonSVG : sunSVG;
+
+    btn.addEventListener('click', () => {
+      const goLight = isDark();
+      document.documentElement.setAttribute('data-theme', goLight ? 'light' : 'dark');
+      localStorage.setItem(STORAGE_KEY, goLight ? 'light' : 'dark');
+
+      /* Swap icon immediately and trigger a gentle rotate via CSS */
+      btn.innerHTML = goLight ? sunSVG : moonSVG;
+      const svg = btn.querySelector('svg');
+      svg.style.transition = 'none';
+      svg.style.transform = 'rotate(-90deg) scale(0.5)';
+      svg.style.opacity = '0';
+      requestAnimationFrame(() => {
+        svg.style.transition = 'transform 0.4s ease, opacity 0.3s ease';
+        svg.style.transform = 'rotate(0deg) scale(1)';
+        svg.style.opacity = '1';
+      });
+    });
+
+    /* Where to place the button */
+    const topbar = document.querySelector('.topbar');
+    if (topbar) {
+      /* Admin-style pages: insert into topbar (CSS handles flex layout) */
+      topbar.appendChild(btn);
+    } else {
+      /* Login / placeholder pages: fixed position */
+      btn.classList.add('theme-toggle--fixed');
+      document.body.appendChild(btn);
+    }
+  }
+
+  if (document.readyState === 'loading') {
+    document.addEventListener('DOMContentLoaded', init);
+  } else {
+    init();
+  }
+})();