/* A black curtain between the website and the separate game page. */
html::after{content:'';position:fixed;inset:0;z-index:2147483647;background:#000;opacity:0;pointer-events:none;transition:opacity .36s ease}
html.demo-leaving::after,html.demo-arriving::after{opacity:1;pointer-events:auto;cursor:wait}
@media(prefers-reduced-motion:reduce){html::after{transition:none}}