body {
  -webkit-touch-callout: none;
  -webkit-tap-highlight-color: #222;
  user-select: none;
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;    
  background: #222;
  color: #eee;
  text-align: center;
}

canvas#main {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);  
  width: 80vmin;
  height: 80vmin;
  image-rendering: -moz-crisp-edges;
  image-rendering: -webkit-optimize-contrast;
  image-rendering: -o-crisp-edges;
  image-rendering: pixelated;
  background: black;
}