代码示例：（标识：css_dropdown_text）
<!DOCTYPE html>
<html>
<head>
<style>
.dropdown {
position: relative;
display: inline-block;
}
.dropdown-content {
display: none;
position: absolute;
background-color: #f9f9f9;
min-width: 160px;
box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
padding: 12px 16px;
z-index: 1;
}
.dropdown:hover .dropdown-content {
display: block;
}
</style>
</head>
<body>
<h1>可悬停的下拉菜单</h1>
<p>请把鼠标移到文本上，已查看下拉内容。</p>
<div class="dropdown">
<span>把鼠标移到我上面</span>
<div class="dropdown-content">
<p>Hello World!</p>
</div>
</div>
</body>
</html>
