body {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
  background-repeat: repeat;  /* image is set by JS onload */
}
canvas {
  display: block;
  margin: 25px auto;

  /* VM resolution is 800x600 */
  width: 800px;
  height: 600px;

  /* fix fuzziness: https://stackoverflow.com/a/13492784 */
  image-rendering: optimizeSpeed;
  image-rendering: -moz-crisp-edges;
  image-rendering: -o-crisp-edges;
  image-rendering: -webkit-optimize-contrast;
  image-rendering: crisp-edges;
  -ms-interpolation-mode: nearest-neighbor;
}
a.github {
  position: fixed;
  right: 16px;
  bottom: 16px;
  text-decoration: none;
}
a.github, a.github svg {
  width: 32px;
  height: 32px;
  fill: #101010;
  fill-opacity: 0.9;
}