CSS - 三角形

实现代码

.icon-arrow{    border:10px solid white;    border-left:6px solid white;    border-right:6px solid white;    border-color:transparent;    position:absolute;    top:-2px;    width:0;    height:0;    margin-left:10px;}.icon-arrow.down{    top:8px;}
 .icon-arrow.down{    border-top-color:green;}