<!DOCTYPE html>
<html lang="en">
<head>
<title>Title</title>
<meta charset="UTF-8">
<style>
.div1{
background-color: #fac237;
height: 1500px;
}
.div2{
background-color: #b18621;
height: 1500px;
}
a{
position: fixed;
bottom: 20px;
right: 20px;
}
</style>
</head>
<body>
<div class="div1"></div>
<div class="div2"></div>
<a>返回顶部</a>
</body>
</html>
原文：https://www.cnblogs.com/zxy01/p/13208848.html