演示代码：
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<style type="text/css">
div{
width: 200px;height: 300px;
margin: 100px auto;
background: #00ff00 url(pkp.png) no-repeat 50% 50%/1100% 500%;
}
</style>
</head>
<body>
<div></div>
</body>
</html>
