#gc-stl-viewer {
    width: 100%;
    height: 400px;
    border-radius: 8px;
    overflow: hidden;
    background: #ffc0cb;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
    margin-top: 12px;
    position: relative;
    touch-action: none;
    -webkit-user-select: none;
    -moz-user-select: none;
    user-select: none;
    transition: background-color 0.3s ease;
  }
  .gc-stl-viewer-wrapper { margin-top: 20px; }
  .gc-stl-viewer-title { font-size: 16px; margin: 0 0 8px 0; font-weight: 600; }
  .gc-stl-error { color: #c62828; padding: 12px; }