html {
      width: 100%;
      height: 100%;
      display: flex;
      justify-content: center;
      align-items: center;
      flex-direction: column;
    }
 body {
      width: 100%;
      height: 100%;
      display: flex;
      justify-content: center;
      align-items: center;
      flex-direction: row;
      margin: 0; 
    }

 canvas {
      max-width: 100%;
      max-height: 100%;
      margin: auto;
      overflow: auto;
      position: fixed;
      object-fit: contain;
      top: 0;
      bottom: 0;
      left: 0;
      right: 0;
    }