html,
body {
  -webkit-touch-callout: none;
  -webkit-user-select: none;
  user-select: none;
  touch-action: none;
}

canvas {
  border: 3px solid #000000;
  border-radius: 20px;
  margin: 20px auto;
  display: block;
  max-width: 90%;
  width: 100%;
  height: auto;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
  cursor: pointer;
  image-rendering: pixelated;
}

/* ゲームコンテナ */
#game-container {
  position: relative;
  width: 100%;
  max-width: 600px;
  margin: 0 auto;
}

#canvas-container {
  position: relative;
  overflow: hidden;
}