순수 CSS를 통해 탐색 모음의 드롭다운 메뉴 효과를 구현하는 방법

<nav class="navbar">
  <ul class="nav-list">
    <li class="nav-item">首页</li>
    <li class="nav-item">产品</li>
    <li class="nav-item dropdown">
      <a href="#" class="dropdown-btn">服务</a>
      <ul class="dropdown-menu">
        <li><a href="#">服务一</a></li>
        <li><a href="#">服务二</a></li>
        <li><a href="#">服务三</a></li>
      </ul>
    </li>
    <li class="nav-item">关于我们</li>
    <li class="nav-item">联系我们</li>
  </ul>
</nav>

.navbar {
  background-color: #f0f0f0;
  padding: 10px;
}

.nav-list {
  list-style-type: none;
  margin: 0;
  padding: 0;
  display: flex;
}

.nav-item {
  margin-right: 10px;
}

.dropdown {
  position: relative;
}

.dropdown > .dropdown-menu {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  background-color: #f0f0f0;
}

.dropdown:hover > .dropdown-menu {
  display: block;
}

.dropdown-menu li {
  padding: 5px;
}

.dropdown-menu a {
  color: #333;
  text-decoration: none;
}

.dropdown-menu a:hover {
  background-color: #ccc;
}