关于使用css伪类实现小图标

效果:

.person_use>span{
    display:block;
    width:0;
    height:0;
    border-width:10px;
    border-style:solid;
    border-color:transparent  transparent #ddd transparent ;
    position:absolute;
    top:-20px;
    left:50%;
    margin-left: -5px;
}
.person_use>span>em{
    display:block;
    width:0;
    height:0;
    border-width: 10px;
    border-style:solid;
    border-color: transparent transparent #fff transparent  ;
    position:absolute;
    top:-9px;
    left:50%;
    margin-left: -9px;
}