如何使用JAVASCRIPT而不是jQuery使div在点击按钮时可展开-可折叠到左侧？

<div>
  <button id="toggleButton">展开/折叠</button>
  <div id="content">这是要展开-折叠的内容</div>
</div>

#content {
  width: 200px;
  height: 200px;
  background-color: #ccc;
  transition: width 0.5s;
}

.collapsed {
  width: 0;
}

var toggleButton = document.getElementById('toggleButton');
var content = document.getElementById('content');

toggleButton.addEventListener('click', function() {
  if (content.classList.contains('collapsed')) {
    content.classList.remove('collapsed');
  } else {
    content.classList.add('collapsed');
  }
});