一个before伪类的超有用应用

就是在水平菜单的选择项中间加上一竖线当作分隔符。

<!doctype html>
<html dir="ltr" lang="zh-CN">
    <head>
        <meta charset="utf-8"/>
        <meta http-equiv="X-UA-Compatible" content="IE=Edge">
        <title>菜单</title>
        <style type="text/css" title="default" media="screen">
            ul { padding:0; margin:0; font:0.9em Verdana; }
            li { display:inline; color:green; }
            li~li:before { content:"|"; padding-right:5px; color:red; }
            li a{ display:block;text-decoration:none;background:#CC99CC;}
            li a{ display:inline;}
        </style>
    </head>  
    <body>
        <ul>
            <li>menu1</li>
            <li><a href="http://www.cnblogs.com/rubylouvre/">menu2</a></li>
            <li>menu3</li>
            <li>menu4</li>
        </ul>
    </body>    
</html>

或利用相邻选择符加after伪类。

由于IE6不支持，我们可以利用负margin技术变通一下，但还是要多添加一个类……

<!doctype html>
<html dir="ltr" lang="zh-CN">
    <head>
        <meta charset="utf-8"/>
        <meta http-equiv="X-UA-Compatible" content="IE=Edge">
        <title>菜单</title>
        <style type="text/css" title="default" media="screen">
            ul { padding:0; margin:0; font:0.9em Verdana; }
            li { display:inline; color:green; padding:0 5px;border-right:1px solid red;margin-left:-1px;}
            li a{ display:block;text-decoration:none;background:#CC99CC;}
            li a{ display:inline;}
            li.last {border-width:0;}
        </style>
    </head>  
    <body>
        <ul>
            <li>menu1</li>
            <li><a href="http://www.cnblogs.com/rubylouvre/">menu2</a></li>
            <li>menu3</li>
            <li class="last">menu4</li>
        </ul>
    </body>    
</html>