body {
  -webkit-touch-callout: none;
  -webkit-tap-highlight-color: #ddd;
  user-select: none;
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  background: #ddd;
  color: black;
  text-align: center;
  overflow-y: hidden;
}

canvas#main {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  width: 80vmin;
  height: 80vmin;
  background: #240059;
}