html,
body {
  width: 100%;
  height: 100%;
  margin: 0;
  overflow: hidden;
  background: #000;
  touch-action: none;
  user-select: none;
  -webkit-user-select: none;
}

body.game-active {
  cursor: crosshair;
}

canvas {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}