body {
      margin: 0;
      font-family: Arial, sans-serif;
    }
    /* Login Page */
    .login-page {
      display: flex;
      justify-content: center;
      align-items: center;
      height: 100vh;
      background: #f4f4f4;
    }
    .login-box {
      background: #fff;
      padding: 30px;
      border-radius: 8px;
      width: 320px;
      box-shadow: 0 0 10px rgba(0,0,0,0.2);
    }
    .login-box h1 {
      text-align: center;
      margin-bottom: 20px;
    }
    .login-box input {
      width: 100%;
      padding: 10px;
      margin: 8px 0;
      border: 1px solid #ccc;
      border-radius: 4px;
    }
    .login-box button {
      width: 100%;
      padding: 10px;
      background: #007BFF;
      color: #fff;
      border: none;
      border-radius: 4px;
      cursor: pointer;
      font-size: 16px;
    }
    .login-box button:hover {
      background: #0056b3;
    }
    .error {
      color: red;
      text-align: center;
      margin-top: 10px;
    }

    /* Dashboard Page */
    .dashboard {
      display: none;
    }
    .header {
      background: #000;
      color: #fff;
      padding: 15px 30px;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .sidebar {
      width: 220px;
      background: #222;
      color: #fff;
      height: 100vh;
      position: fixed;
      top: 0;
      left: 0;
      padding-top: 60px;
    }
    .sidebar ul {
      list-style: none;
      padding: 0;
    }
    .sidebar ul li {
      padding: 12px 20px;
      cursor: pointer;
    }
    .sidebar ul li:hover {
      background: #444;
    }
    .main {
      margin-left: 220px;
      padding: 20px;
    }
    .card {
      background: #fff;
      padding: 20px;
      margin-bottom: 20px;
      border-radius: 6px;
      box-shadow: 0 0 5px rgba(0,0,0,0.1);
    }
    .card h2 {
      margin-top: 0;
    }