html,body{background:#000;height:100%;margin:0;overflow:hidden}canvas{width:100%;height:100%;display:none}#start-overlay{color:#fff;cursor:pointer;z-index:9999;background:#000c;justify-content:center;align-items:center;width:100%;height:100%;font-size:2rem;display:flex;position:fixed;top:0;left:0}