html, body {
      margin: 0;
      padding: 0;
      height: 100vh;
      display: flex;
      flex-direction: column;
      font-family: sans-serif;
      background: #ffffff;
    }

    .viewer-container {
      flex: 1 1 auto;
      position: relative;
      width: 100%;
      cursor: url('cursor.cur'), auto;
    }

    model-viewer {
      width: 100%;
      height: 100%;
      background-color: #fff;
    }

    .upload-container {
      margin: 12px 0 0;
      display: flex;
      justify-content: center;
      align-items: center;
    }

    .modern-upload-btn {
      background-color: #3FF2C8;
      color: #fff;
      font-weight: 600;
      font-size: 16px;
      padding: 10px 26px;
      border-radius: 12px;
      border: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 10px;
      transition: all 0.3s ease;
      box-shadow: 0px 6px 14px rgba(63, 242, 200, 0.25);
      font-family: 'Inter', sans-serif;
    }

    .modern-upload-btn:hover {
      background-color: #5ff3d4;
      transform: scale(1.03);
      box-shadow: 0px 8px 24px rgba(63, 242, 200, 0.4);
    }

    .modern-upload-btn:active {
      transform: scale(0.96);
    }

    .modern-upload-btn:disabled {
      background-color: #ccc !important;
      color: #f0f0f0;
      cursor: not-allowed;
      opacity: 0.7;
    }

    .icon-arrow::after {
      content: '→';
      font-size: 18px;
      display: inline-block;
    }

    .thumb-nav {
      margin: 12px 0 16px;
      display: flex;
      justify-content: center;
      gap: 1rem;
      width: 100%;
      max-width: 900px;
      padding: 0 1rem;
      box-sizing: border-box;
      margin-left: auto;
      margin-right: auto;
      flex-wrap: wrap;
    }

    .model-thumb {
      aspect-ratio: 2 / 1;
      width: 200px;
      object-fit: contain;
      border-radius: 16px;
      cursor: pointer;
      border: 2px solid transparent;
      transition: 0.2s ease;
      box-sizing: border-box;
      background: #fff;
      padding: 6px;
      box-shadow: 0 0 6px rgba(0, 0, 0, 0.05);
    }

    .model-thumb.selected {
      border-color: #3FF2C8;
    }

    .side-arrow {
      position: absolute;
      top: 50%;
      transform: translateY(-50%);
      background-color: white;
      border: none;
      font-size: 32px;
      cursor: pointer;
      border-radius: 50%;
      width: 50px;
      height: 50px;
      box-shadow: 0 2px 8px rgba(0,0,0,0.1);
      z-index: 15;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .left-arrow { left: 16px; }
    .right-arrow { right: 16px; }

    @media screen and (max-width: 768px) {
      .model-thumb {
        width: 22%;
        padding: 4px;
      }

      .thumb-nav {
        gap: 1rem;
        max-width: 100%;
        flex-wrap: nowrap;
        overflow-x: auto;
        justify-content: center;
        padding: 0 1rem;
      }

      .thumb-nav::-webkit-scrollbar {
        display: none;
      }

      .thumb-nav {
        scrollbar-width: none;
        -ms-overflow-style: none;
      }

      .modern-upload-btn {
        font-size: 12px;
        padding: 5px 10px;
        border-radius: 10px;
        gap: 6px;
      }

      .icon-arrow::after {
        font-size: 16px;
      }

      .side-arrow {
        width: 44px;
        height: 44px;
        font-size: 24px;
        background-color: rgba(255, 255, 255, 0.85);
        color: #333;
      }

      .left-arrow { left: 2px; }
      .right-arrow { right: 2px; }
    }

    @media screen and (max-width: 508px) {
      .model-thumb {
        aspect-ratio: 1 / 1;
        width: 23%;
        padding: 4px;
      }
    }

    model-viewer::part(default-ar-button) {
      position: absolute;
      top: 16px;
      right: 16px;
      transform: none;
      margin: 0;
      z-index: 20;
      width: 60px;
      height: 60px;
      font-size: 44px;
      padding: 12px;
      border-radius: 40px;
    }

    model-viewer::part(default-ar-button) #view_x5F_in_x5F_AR_x5F_icon {
      width: 32px;
      height: 32px;
    }