:root{--g1: black;--g2: #333333}@keyframes background-pan{0%{background-position:0%,center}to{background-position:-200%,center}}body{animation:background-pan 10s linear infinite;background:linear-gradient(to right,var(--g1),var(--g2),var(--g1));margin:0;overflow:hidden;background-size:200%}.tile:before{background-color:#0a0a0a;content:"";position:absolute;inset:.5px}.tile{position:relative}#tiles{display:grid;height:100vh;width:100vw;grid-template-columns:repeat(var(--columns),1fr);grid-template-rows:repeat(var(--rows),1fr)}