:root { color-scheme: dark; background: #111512; }
* { box-sizing: border-box; }
html, body { width: 100%; height: 100%; margin: 0; overflow: hidden; }
#board { display: block; width: 100%; height: 100%; height: 100dvh; cursor: crosshair; touch-action: none; outline: none; }
#board:focus-visible { box-shadow: inset 0 0 0 2px #70816d; }