body {
  margin: 0;
  background: linear-gradient(to bottom, #111, #333);
  font-family: sans-serif;
  color: white;
  text-align: center;
}
canvas {
  width: 100%;
  height: auto;
  max-width: 800px;
  aspect-ratio: 4 / 3;
  display: block;
  margin: 0 auto;
  background: #111;
  box-shadow: 0 0 30px rgba(0,0,0,0.8);
  touch-action: none;
}
#scoreboard {
  font-size: 2em;
  margin: 20px 0;
}
#controls button {
  margin: 10px;
  padding: 10px 20px;
  font-size: 1em;
}