/** Thanks @jsliang for the CSS snippet to keep the canvas centered **/
html {margin: 0; padding: 0;}
body {
  margin: 0;
  padding: 0;
  background-color: white;
  /* leave it to hide the scrollbars */
  overflow: hidden;
}

canvas {
  max-width: 100%;
  max-height: 100%;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  object-fit: contain;
}