<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟学堂()</title>
<style>
div
{
width:300px;
height:100px;
background-color:yellow;
box-shadow: 10px 10px 5px #888888;
}
</style>
</head>
<body>
<div></div>
</body>
</html>