body {
  margin: 0;
  padding: 0;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  background-color: #222;
}

#game-container {
  box-shadow: 0 0 20px rgba(0, 0, 0, 0.8);
  /* The original game resolution is 432x304 usually, but prompt specified 640x432 */
  width: 640px;
  height: 432px;
}

canvas {
  display: block;
  background-color: #87CEEB; /* Sky blue placeholder */
}