* { margin: 0; padding: 0; box-sizing: border-box; }
body {
  background: #1a1a2e;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
}
canvas {
  display: block;
  image-rendering: pixelated;
  border: 2px solid #444;
}