线带下三角CSS样式

示例

样式及html:

<style>  
#b0{border-top:#999 solid 1px;padding-left:100px;}
#b1{width:0px;height:0px;border-left:15px solid transparent;border-right:15px solid transparent;border-top:10px solid #999;position:relative;} 
#b2{width:0px;height:0px;border-left:15px solid transparent;border-right:15px solid transparent;border-top:10px solid #fff;position:absolute;top:-11px;left:-15px;} 
</style>  
<div id="b0">  
    <div id="b1">
        <div id="b2"></div>
    </div>
</div>