* { margin: 0; padding: 0; box-sizing: border-box; }
  html { width: 100%; height: 100%; overflow: hidden; }
  body { background: #000; display: flex; justify-content: center; align-items: center;
         width: 100%; height: 100%; overflow: hidden;
         font-family: 'Courier New', monospace; user-select: none; touch-action: none; }
  canvas { display: block; image-rendering: pixelated; max-width: 100%; max-height: 100%; }