/* One viewport-sized animated backdrop stays visible throughout scrolling. */
body{position:relative;isolation:isolate;min-height:100vh}
body > canvas.ascii-bg{position:fixed;inset:0;width:100%;height:100vh;height:100dvh;pointer-events:none;z-index:-1;opacity:.55;-webkit-mask-image:linear-gradient(90deg,#000,rgba(0,0,0,.16) 35%,rgba(0,0,0,.16) 65%,#000);mask-image:linear-gradient(90deg,#000,rgba(0,0,0,.16) 35%,rgba(0,0,0,.16) 65%,#000)}
html.embed body > canvas.ascii-bg{display:none}
@media print{body > canvas.ascii-bg{display:none}}