body {
  /* Allow canvas to hit the edges of the browser viewport. */
  margin: 0;
}

#screen canvas {
  margin: auto;

  /* Hide the gap for font descenders. */
  display: block;

  /* disable scaling interpolation */
  image-rendering: optimizeSpeed;
  image-rendering: -moz-crisp-edges;
  image-rendering: -o-crisp-edges;
  image-rendering: -webkit-optimize-contrast;
  image-rendering: optimize-contrast;
  image-rendering: pixelated;
  -ms-interpolation-mode: nearest-neighbor;
}