在这里插入代码片<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>回到顶部</title>
<style>
*{margin: 0;
padding: 0;
}
.container{
width: 1200px;
height: 100%;
margin:0 auto;
}
.header{
height: 200px;
}
.nav{
height: 80px;
}
.content{
height: 900px;
}
.footer{
height: 240px;
}
.header .container{
background-color: orange;
}
.nav .container{
background-color: gray;
}
.content .container{
background-color: yellow;
}
.footer .container{
background:
}
.t{
line-height: 80px;
width: 80px;
border:1px solid
position: fixed;
right: 50px;
bottom:50px;
text-align: center;
background:
}
</style>
</head>
<body>
<div class="header"><div class="container">头部</div></div>
<div class="nav"><div class="container">导航</div></div>
<div class="content"><div class="container">内容</div></div>
<div class="footer"><div class="container">页脚</div></div>
<div class="t">TOP</div>
<script src="http://libs.baidu.com/jquery/2.0.0/jquery.js" type="text/javascript" charset="utf-8"></script>
<script type="text/javascript">
$(function(){
$(".t").on("click",function(){
$("html").animate({"scrollTop":0},1000);
})
$(window).scroll(function(){
var str=$(window).scrollTop();
if(str>300){
$(".t").show();
}else{
$(".t").hide();
}
})
})
</script>
</body>
</html>``
