css制作小标志

<b class="bottom"><i class="bottom-arrow1"></i><i class="bottom-arrow2"></i></b>

.post_list .spread .bottom{
    width:20px;
    height:20px;
    position:absolute;
    left:24px;
    top: .06rem;
    z-index: 2;/*兼容ie8-*/
}
.post_list .spread .bottom-arrow1,.bottom-arrow2{
    width:0;
    height:0;
    display:block;
    position:absolute;
    left:0;
    top:0;
    z-index: 5;/*兼容ie8-*/
    border-bottom:.13rem transparent dashed;
    border-left:.13rem transparent dashed;
    border-right:.13rem transparent dashed;
    border-top:.13rem white solid;
    overflow:hidden;
}
.post_list .spread .bottom-arrow1{
    top:1px;/*重要*/
    border-top:.13rem blue solid;
}
.post_list .spread .bottom-arrow2{
    border-top:.13rem white solid;
}

<div class="test"></div>

.test{
    display: inline-block;
    vertical-align: middle;
    margin-top: -1px;
    margin-left: 6px;
    margin-right: -14px;
    width: 0;
    height: 0;
    border-left: 4px solid transparent;
    border-right: 4px solid transparent;
    border-top: 5px solid #ccc;
}