HTML代码
<!DOCTYPE html>
<html>
<head>
<link type="text/css" rel="stylesheet" href="style.css">
</head>
<body>
<div id="box1"> </div>
</body>
</html>
CSS代码
#box1 {
width: 600px;
height: 200px;
background-color: lightgrey;
box-shadow: inset 0 0 15px black;
}