如何使用CSS转换侧边栏菜单？

<div class="sidebar">
  <ul>
    <li><a href="#">菜单项1</a></li>
    <li><a href="#">菜单项2</a></li>
    <li><a href="#">菜单项3</a></li>
    <li><a href="#">菜单项4</a></li>
  </ul>
</div>

.sidebar {
  width: 200px;
  height: 100vh;
  background-color: #f2f2f2;
}

ul {
  list-style-type: none;
  padding: 0;
  margin: 0;
}

li {
  height: 40px;
  line-height: 40px;
  padding: 0 20px;
  border-bottom: 1px solid #ccc;
}

li a {
  text-decoration: none;
  color: #333;
}

li:hover {
  background-color: #ccc;
}

li:hover a {
  color: #fff;
  transition: color 0.3s ease;
}