<!DOCTYPE html>
<html>
<head>
<style>
div {
width: 300px;
height: 100px;
padding: 15px;
background-color: yellow;
box-shadow: 10px 10px grey;
}
</style>
</head>
<body>
<div>已设置 box-shadow 的 div 元素</div>
</body>
</html>