html, body {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
}

canvas {
  display: block;
  top: 0;
  left: 0;
}



/* Home 按钮，固定在左上角 */
#homeButton {
  position: absolute;
  top: 20px;
  left: 20px;
  padding: 10px 20px;
  font-size: 16px;
  background-color: #00aaff;
  border: none;
  border-radius: 5px;
  color: white;
  cursor: pointer;
}

#homeButton:hover {
  background-color: #0088cc;
}

/* How to Play 按钮，固定在右上角 */
#helpButton {
  position: absolute;
  top: 20px;
  right: 20px;
  padding: 10px 20px;
  font-size: 16px;
  background-color: #ffcc00;
  border: none;
  border-radius: 5px;
  cursor: pointer;
}

#helpButton:hover {
  background-color: #ffaa00;
}

/* 教程弹窗 */
#helpOverlay {
  display: none; /* 初始隐藏 */
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.7);
  display: flex;
  justify-content: center;
  align-items: center;
}

#helpContent {
  background: white;
  padding: 20px;
  border-radius: 10px;
  max-width: 400px;
  text-align: center;
}

#helpContent h2 {
  margin-top: 0;
}

#helpContent ul {
  list-style: none;
  padding: 0;
  text-align: left;
}

#helpContent li {
  margin: 10px 0;
}

/* 关闭按钮 */
#closeHelp {
  margin-top: 10px;
  padding: 8px 15px;
  font-size: 14px;
  background-color: #ff4500;
  border: none;
  color: white;
  border-radius: 5px;
  cursor: pointer;
}

#closeHelp:hover {
  background-color: #cc3700;
}