* {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
      background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
      min-height: 100vh;
      padding: 2rem;
    }
    .container {
      max-width: 1400px;
      margin: 0 auto;
    }
    .header {
      text-align: center;
      color: white;
      margin-bottom: 3rem;
    }
    .header h1 {
      font-size: 3rem;
      margin-bottom: 1rem;
      text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
    }
    .header p {
      font-size: 1.2rem;
      opacity: 0.9;
    }
    .stats-bar {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
      gap: 1.5rem;
      margin-bottom: 2rem;
    }
    .stat-card {
      background: white;
      padding: 1.5rem;
      border-radius: 12px;
      box-shadow: 0 4px 6px rgba(0,0,0,0.1);
      text-align: center;
    }
    .stat-card i {
      font-size: 2.5rem;
      color: #667eea;
      margin-bottom: 0.5rem;
    }
    .stat-card .number {
      font-size: 2rem;
      font-weight: bold;
      color: #333;
    }
    .stat-card .label {
      color: #666;
      font-size: 0.9rem;
      margin-top: 0.5rem;
    }
    .main-content {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 2rem;
      margin-bottom: 2rem;
    }
    .card {
      background: white;
      border-radius: 12px;
      padding: 2rem;
      box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    }
    .card-header {
      display: flex;
      align-items: center;
      gap: 1rem;
      margin-bottom: 1.5rem;
      padding-bottom: 1rem;
      border-bottom: 2px solid #f0f0f0;
    }
    .card-header i {
      font-size: 2rem;
      color: #667eea;
    }
    .card-header h2 {
      font-size: 1.5rem;
      color: #333;
    }
    .progress-bar {
      width: 100%;
      height: 30px;
      background: #f0f0f0;
      border-radius: 15px;
      overflow: hidden;
      margin: 1rem 0;
    }
    .progress-fill {
      height: 100%;
      background: linear-gradient(90deg, #667eea, #764ba2);
      transition: width 0.3s ease;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-weight: bold;
    }
    .topic-list {
      list-style: none;
    }
    .topic-item {
      padding: 1rem;
      margin: 0.5rem 0;
      background: #f8f9fa;
      border-radius: 8px;
      cursor: pointer;
      transition: all 0.3s;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .topic-item:hover {
      background: #e9ecef;
      transform: translateX(5px);
    }
    .topic-item.completed {
      background: #d4edda;
      border-left: 4px solid #28a745;
    }
    .topic-item.in-progress {
      background: #fff3cd;
      border-left: 4px solid #ffc107;
    }
    .topic-item.locked {
      background: #f8f9fa;
      opacity: 0.6;
      cursor: not-allowed;
    }
    .badge {
      display: inline-block;
      padding: 0.25rem 0.75rem;
      border-radius: 12px;
      font-size: 0.85rem;
      font-weight: bold;
    }
    .badge-success {
      background: #28a745;
      color: white;
    }
    .badge-warning {
      background: #ffc107;
      color: #333;
    }
    .badge-info {
      background: #17a2b8;
      color: white;
    }
    .btn {
      padding: 0.75rem 1.5rem;
      border: none;
      border-radius: 8px;
      font-size: 1rem;
      cursor: pointer;
      transition: all 0.3s;
      font-weight: bold;
    }
    .btn-primary {
      background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
      color: white;
    }
    .btn-primary:hover {
      transform: translateY(-2px);
      box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
    }
    .btn-success {
      background: #28a745;
      color: white;
    }
    .btn-success:hover {
      background: #218838;
    }
    .exam-card {
      background: white;
      border-radius: 12px;
      padding: 1.5rem;
      margin: 1rem 0;
      box-shadow: 0 2px 4px rgba(0,0,0,0.1);
      cursor: pointer;
      transition: all 0.3s;
    }
    .exam-card:hover {
      transform: translateY(-3px);
      box-shadow: 0 6px 12px rgba(0,0,0,0.15);
    }
    .exam-header {
      display: flex;
      justify-content: space-between;
      align-items: center;
      margin-bottom: 1rem;
    }
    .exam-title {
      font-size: 1.2rem;
      font-weight: bold;
      color: #333;
    }
    .exam-meta {
      display: flex;
      gap: 1rem;
      color: #666;
      font-size: 0.9rem;
    }
    .achievements {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
      gap: 1rem;
      margin-top: 1rem;
    }
    .achievement {
      text-align: center;
      padding: 1rem;
      background: #f8f9fa;
      border-radius: 8px;
    }
    .achievement.locked {
      opacity: 0.5;
      filter: grayscale(100%);
    }
    .achievement i {
      font-size: 2.5rem;
      margin-bottom: 0.5rem;
    }
    .achievement.unlocked i {
      color: #ffc107;
    }
    .modal {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: rgba(0,0,0,0.5);
      z-index: 1000;
      align-items: center;
      justify-content: center;
    }
    .modal.active {
      display: flex;
    }
    .modal-content {
      background: white;
      border-radius: 12px;
      padding: 2rem;
      max-width: 800px;
      width: 90%;
      max-height: 90vh;
      overflow-y: auto;
    }
    .close-btn {
      float: right;
      font-size: 1.5rem;
      cursor: pointer;
      color: #666;
    }
    @media (max-width: 768px) {
      .main-content {
        grid-template-columns: 1fr;
      }
      .header h1 {
        font-size: 2rem;
      }
    }