 var(--body-color);
      }

      #canvas {
        position: absolute;
        top: 0;
        left: 0;
        height: 100%;
        width: 100%;
        background-color: black;
      }

      .control-panel {
        display: flex;
        flex-direction: row;

        /* do not touch opacity. it breaks backdrop-filter in chrome/firefox */
        visibility: hidden;
        opacity: 1;
        transition: 0.3s opacity, 0.3s visibility;

        margin-left: 0.3rem;
        margin-right: 0.3rem;
      