<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<style type="text/css">
*{
margin: 0;
padding: 0;
}
body{
background: #ddd;
}
ul{
list-style: none;
}
a{
text-decoration: none;
}
.box{
margin: 0 auto;
width: 1200px;
}
.fl_l{
width: 200px;
float: left;
border: 1px solid #f4f4f4;
background: #fff;
position: fixed;
top: 0;
left: 0;
}
.fl_l li a{
border-bottom: 1px solid #eee;
text-align: center;
display: block;
color: #333;
font-size: 14px;
line-height: 60px;
}
.fl_l li.active a{
background: #f60;
color: #fff;
}
.fl_r{
float: right;
width: 960px;
}
.fl_r li{
margin-bottom: 30px;
background: #fff;
font-size: 50px;
line-height: 300px;
display: block;
text-align: center;
}
</style>
</head>
<body>
<div class="box">
<ul class="fl_l">
<li class="active"><a href="##">菜單1</a></li>
<li><a href="##">菜單2</a></li>
<li><a href="##">菜單3</a></li>
<li><a href="##">菜單4</a></li>
</ul>
<ul class="fl_r">
<li style="height: 600px;">菜單1內容</li>
<li style="height: 600px;">菜單2內容</li>
<li style="height: 400px;">菜單3內容</li>
<li style="height: 500px;">菜單4內容</li>
</ul>
<div style="clear: both;"></div>
</div>
<script src="jquery-1.10.1.min.js"></script>
<script type="text/javascript">
$(function(){
$(window).scroll(function(){
$('.fl_l li').eq(0).addClass('active');
//左側導航加active
$('.fl_r li').each(function(){
var _target=parseInt($(this).offset().top-$(window).scrollTop());
var _i=$(this).index();
if (_target<=0) {
$('.fl_l li').removeClass('active');
$('.fl_l li').eq(_i).addClass('active');
}
//如果到達頁面底部，給左側導航最後一個加active
else if($(document).height()==$(window).scrollTop()+$(window).height()){
$('.fl_l li').removeClass('active');
$('.fl_l li').eq($('.fl_r li').length-1).addClass('active');
}
});
});
$('.fl_l li').click(function(){
$(this).addClass('active').siblings().removeClass('active');
var _i=$(this).index();
$('body, html').animate({scrollTop:$('.fl_r li').eq(_i).offset().top},500);
});
});
</script>
</body>
</html>
