body {
      background: linear-gradient(135deg, #dbeafe, #f8fafc);
      padding: 20px 0;
    }

    .header-section {
      background: white;
      border-radius: 20px;
      padding: 30px;
      margin-bottom: 30px;
      box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    }

    .header-section h1 {
      font-size: 28px;
      font-weight: 700;
      color: #2d3748;
      margin-bottom: 10px;
    }

    .header-section p {
      color: #718096;
      margin: 0;
      font-size: 14px;
    }

    .locker-grid {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
      gap: 15px;
      margin-top: 20px;
    }

    .locker-card {
      background: white;
      border-radius: 15px;
      padding: 25px 20px;
      text-align: center;
      transition: all 0.3s ease;
      box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
      border: 3px solid transparent;
      cursor: pointer;
      position: relative;
      overflow: hidden;
    }

    .locker-card::before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      right: 0;
      height: 5px;
      background: linear-gradient(90deg, #667eea 0%, #764ba2 100%);
      transform: scaleX(0);
      transition: transform 0.3s ease;
    }

    .locker-card:hover {
      transform: translateY(-5px);
      box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
      border-color: #667eea;
    }

    .locker-card:hover::before {
      transform: scaleX(1);
    }

    .locker-icon {
      font-size: 48px;
      margin-bottom: 15px;
      display: block;
    }

    .locker-number {
      font-size: 24px;
      font-weight: 700;
      color: #2d3748;
      margin-bottom: 8px;
    }

    .locker-status {
      display: inline-block;
      padding: 5px 15px;
      border-radius: 20px;
      font-size: 12px;
      font-weight: 600;
      margin-bottom: 15px;
    }

    .status-available {
      background: #c6f6d5;
      color: #22543d;
    }

    .status-occupied {
      background: #fed7d7;
      color: #742a2a;
      pointer-events: none;
      opacity: 0.6;
    }

    .locker-card.occupied {
      opacity: 0.5;
      cursor: not-allowed;
    }

    .locker-card.occupied:hover {
      transform: none;
      border-color: transparent;
    }

    .select-btn {
      background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
      color: white;
      border: none;
      padding: 10px 25px;
      border-radius: 10px;
      font-weight: 600;
      font-size: 14px;
      transition: all 0.3s ease;
      width: 100%;
    }

    .select-btn:hover {
      background: linear-gradient(135deg, #5568d3 0%, #633b8f 100%);
      transform: scale(1.05);
    }

    .select-btn:disabled {
      background: #e2e8f0;
      color: #a0aec0;
      cursor: not-allowed;
    }

    .empty-state {
      background: white;
      border-radius: 15px;
      padding: 60px 30px;
      text-align: center;
      box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    }

    .empty-state-icon {
      font-size: 80px;
      margin-bottom: 20px;
    }

    .empty-state h3 {
      color: #2d3748;
      margin-bottom: 10px;
    }

    .empty-state p {
      color: #718096;
      margin-bottom: 20px;
    }

    .container-custom {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
      position: relative;
    }

    /* Mobile Responsive */
    @media (max-width: 768px) {
      .locker-grid {
        grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
        gap: 12px;
      }

      .header-section {
        padding: 25px 20px;
        border-radius: 15px;
      }

      .header-section h1 {
        font-size: 24px;
      }

      .locker-card {
        padding: 20px 15px;
      }

      .locker-icon {
        font-size: 40px;
      }

      .locker-number {
        font-size: 20px;
      }
    }

    @media (max-width: 480px) {
      .locker-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 10px;
      }

      .header-section {
        padding: 20px 15px;
      }

      .header-section h1 {
        font-size: 20px;
      }

      .header-section p {
        font-size: 13px;
      }

      .locker-card {
        padding: 15px 10px;
      }

      .locker-icon {
        font-size: 36px;
        margin-bottom: 10px;
      }

      .locker-number {
        font-size: 18px;
        margin-bottom: 5px;
      }

      .locker-status {
        font-size: 11px;
        padding: 4px 12px;
        margin-bottom: 10px;
      }

      .select-btn {
        padding: 8px 20px;
        font-size: 13px;
      }
    }

    /* Loading Animation */
    @keyframes pulse {

      0%,
      100% {
        opacity: 1;
      }

      50% {
        opacity: 0.5;
      }
    }

    .loading {
      animation: pulse 1.5s ease-in-out infinite;
    }