<html>
<head>
<style>
.descendants *
{
display: block;
border: 2px solid lightgrey;
color: lightgrey;
padding: 5px;
margin: 15px;
}
</style>
<script src="https://libs.baidu.com/jquery/1.10.2/jquery.min.js">
</script>
<script>
$(document).ready(function(){
$("div").children().css({"color":"red","border":"2px solid red"});
});
</script>
</head>
<body>
<div class="descendants" style="width:500px;">div (current element)
<p>p (child)
<span>span (grandchild)</span>
</p>
<p>p (child)
<span>span (grandchild)</span>
</p>
</div>
</body>
</html>