可折叠的div css -需要它，所以开始关闭

<div class="collapsible">
  <button class="collapsible-btn">展开/折叠</button>
  <div class="collapsible-content">
    <!-- 折叠内容 -->
  </div>
</div>

.collapsible-content {
  display: none; /* 默认折叠起来 */
}

.collapsible-btn {
  background-color: #f1f1f1;
  color: #333;
  padding: 10px;
  border: none;
  cursor: pointer;
}

.collapsible-btn:hover {
  background-color: #ddd;
}

.collapsible-content.show {
  display: block; /* 展开时显示内容 */
}

document.querySelector('.collapsible-btn').addEventListener('click', function() {
  var content = this.nextElementSibling;
  content.classList.toggle('show');
});