.pong-canvas {
  width: min(640px, 100%);
  height: auto;
  aspect-ratio: 640 / 400;
  border: 1px solid var(--hairline);
  border-radius: var(--radius-lg);
  background: var(--canvas-night);
  box-shadow: var(--shadow-md);
  touch-action: none;
  cursor: crosshair;
}