* { margin: 0; padding: 0; box-sizing: border-box; }
body { background: #000; overflow: hidden; }
#game { position: relative; width: 100vw; height: 100vh; }
#g, #hud { position: absolute; top: 0; left: 0; width: 100%; height: 100%; }
#g { z-index: 1; }
#hud { z-index: 2; pointer-events: none; }