html,body{margin:0;height:100%;background:#000;overflow:hidden;overscroll-behavior:none;
  -webkit-user-select:none;user-select:none;-webkit-touch-callout:none;-webkit-tap-highlight-color:transparent}
canvas{position:fixed;left:50%;top:50%;transform:translate(-50%,-50%);touch-action:none;image-rendering:auto}