<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
<title>Document</title>
<style type="text/css">
.backtop{
position: fixed;
bottom: 100px;
right: 30px;
width: 60px;
height: 60px;
background-color: gray;
text-align: center;
line-height:30px;
color:white;
text-decoration: none;
}
</style>
</head>
<body>
<a class="backtop">返回<br />顶部</a>
<img src="images/2.jpg" alt="" />
<img src="images/2.jpg" alt="" />
<img src="images/2.jpg" alt="" />
<img src="images/2.jpg" alt="" />
</body>
</html>
<!DOCTYPE html PUBLIC "-//W