body {
  margin: 0;
  overflow: hidden;
  background-color: #000;
}

canvas {
  display: block;
}

/* 添加按钮样式 */
#viewToggleBtn {
  position: absolute;
  top: 20px;
  left: 20px; /* 关键修改：从右边移到左边 */
  z-index: 100;
  padding: 10px 20px;
  background: rgba(0, 0, 0, 0.7);
  color: white;
  border: 2px solid #ffffff;
  border-radius: 5px;
  cursor: pointer;
  font-size: 16px;
  transition: all 0.3s ease;
}

#viewToggleBtn:hover {
  background: rgba(30, 30, 30, 0.9);
  transform: scale(1.05);
}