* { margin: 0; padding: 0; box-sizing: border-box; }
html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: #000;
  touch-action: none;
  -webkit-user-select: none;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
}
#game {
  display: block;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  touch-action: none;
}