html, body {
  margin: 0; padding: 0; height: 100%;
  background: #05050a;
  overflow: hidden;
  display: flex; align-items: center; justify-content: center;
  font-family: "Courier New", monospace;
}
canvas {
  background: #0a0a12;
  image-rendering: pixelated;
  max-width: 100vw;
  max-height: 100vh;
  aspect-ratio: 3 / 2;
  cursor: crosshair;
  box-shadow: 0 0 40px #0ff3, 0 0 120px #f0f2;
}