* {
        padding: 0;
        margin: 0;
      }
      canvas {
        background: #eeeeee;
        display: block;
        margin: 0 auto;
      }
      .hidden {
        display:none;
      }
      .element {
        display:none;
        position:absolute;
        bottom:40px;
        left:50%;
        transform:translateX(-50%);
        background:white;
        border:2px solid #333;
        padding:20px;
        z-index:10;
        width: 100px"
      }