<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>Document</title> <style> *{margin:0;padding: 0;list-style: none;text-decoration: none} .nav{width: 100%;height: 3rem;background-color: #ddd} .nav ul{width: 70%;height: 3rem;margin: 0 auto;} .nav ul li{float: left;width: 14.28%;height: 3rem;text-align: center;line-height: 3rem;position: relative} .nav li a{display: inline-block;width: 100%;} .nav li span{height: 2px;width: 0;background-color: #000;position: absolute;top:2.9rem;left:50%;} .active{background-color: red;} </style> </head> <body> <div class="nav"> <ul> <li class="t active"><a href="#">星期一</a><span></span></li> <li class="t"><a href="#">星期二</a><span></span></li> <li class="t"><a href="#">星期三</a><span></span></li> <li class="t"><a href="#">星期四</a><span></span></li> <li class="t"><a href="#">星期五</a><span></span></li> <li class="t"><a href="#">星期六</a><span></span></li> <li class="t"><a href="#">星期日</a><span></span></li> </ul> </div> <script src="https://cdn.bootcss.com/jquery/3.2.1/jquery.min.js"></script> <script> $(".t").hover(function(){ $("span",this).animate({ left:'0', width:'100%', right:'0' },500); },function(){ $("span",this).stop().animate({ left:'50%', width:'0', },200); }) $('.t').click(function(){ $('li').removeClass('active'); $(this).addClass('active'); return false; }) </script> </body> </html>
結果以下:css