/* Fullscreen overlay */
    .loading-overlay {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: rgba(255, 255, 255, 0.95);
      display: flex;
      justify-content: center;
      align-items: center;
      z-index: 9999;
      transition: opacity 0.5s ease, visibility 0.5s ease;
    }

    /* Hidden state */
    .loading-overlay.hidden {
      opacity: 0;
      visibility: hidden;
    }

    /* Spinner */
    .spinner {
      width: 50px;
      height: 50px;
      border: 6px solid #ddd;
      border-top: 6px solid #3498db;
      border-radius: 50%;
      animation: spin 1s linear infinite;
    }

    @keyframes spin {
      100% {
        transform: rotate(360deg);
      }
    }