html, body { margin: 0; width: 100%; height: 100%; overflow: hidden; background: #000; }
#game-shell { width: 100%; height: 100%; display: grid; place-items: center; }
canvas { display: block; width: min(100vw, calc(100dvh * 16 / 9)); height: min(100dvh, calc(100vw * 9 / 16)); outline: none; }