body, html {
  margin: 0;
  padding: 0;
  background: #111;
  height: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
  font-family: Arial;
}

.game-wrapper {
  width: 100%;
  max-width: 768px;
  aspect-ratio: 3 / 4;
  background-color: #000;
}

canvas {
  width: 100%;
  height: 100%;
  display: block;
}