:root { color-scheme: dark; background: #24305e; }
* { box-sizing: border-box; }
html, body { width: 100%; height: 100%; margin: 0; overflow: hidden; }
body { touch-action: none; user-select: none; }
canvas { display: block; width: 100%; height: 100%; image-rendering: pixelated; }
#error { position: absolute; inset: auto 20px 20px; margin: 0; padding: 16px; color: #fff4d6; background: #2b2742; font: 15px/1.6 "Microsoft YaHei", sans-serif; }
#error[hidden] { display: none; }