body {
      margin: 0;
      min-height: 100vh;
      font-family: Arial, sans-serif;
      background: #f5f5f5;
    }

    .demo-content {
      min-height: 100vh;
      display: flex;
      align-items: center;
      justify-content: center;
      text-align: center;
    }



    /* Vimeo 隱藏 */
    .vimeo-audio {
      position: fixed;
      width: 1px;
      height: 1px;
      opacity: 0;
      pointer-events: none;
      overflow: hidden;
    }

    .music-btn {
      position: fixed;
      right: 24px;
      bottom: 24px;
      z-index: 9999;

      width: 52px;
      height: 52px;

      display: flex;
      align-items: center;
      justify-content: center;

      padding: 0;
      border: 0;
      border-radius: 50%;

      background: rgba(0, 0, 0, 0.75);
      color: #fff;

      cursor: pointer;

      transition:
        transform 0.3s ease,
        background 0.3s ease;
    }

    @media (hover: hover) and (pointer: fine) {
      .music-btn:hover {
        transform: scale(1.08);
        background: rgba(0, 0, 0, 0.9);
      }
    }


    .music-btn svg {
      width: 22px;
      height: 22px;
      fill: currentColor;
    }

    .music-btn .icon-pause {
      display: none;
    }

    .music-btn.is-playing .icon-play {
      display: none;
    }

    .music-btn.is-playing .icon-pause {
      display: block;
    }