在线运行代码 - 菜鸟教程

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(cainiaoplay.com)</title>
<style>.descendants *{ 
	display: block;
	border: 2px solid lightgrey;
	color: lightgrey;
	padding: 5px;
	margin: 15px;
}
</style>
<script src="https://cdn.staticfile.org/jquery/1.10.2/jquery.min.js">
</script>
<script>
$(document).ready(function(){
	$("ul").children().css({"color":"red","border":"2px solid red"});
});
</script>
</head>
<body class="descendants">body (曾祖先节点)
	
<div style="width:500px;">div (祖先节点)
	<ul>ul (直接父节点)  
		<li>li (子节点)
			<span>span (孙节点)</span>
		</li>
	</ul>   
</div>
	
</body>
</html>
源代码

动行结果
