.underline{ position:relative; }
.underline:after {
position: absolute;
bottom: 0;
left: 20px;
right: 20px;
height: 1px;
content: '';
-webkit-transform: scaleY(.5);
transform: scaleY(.5);
background-color: #e3e5e9; //这个是唯佳的线颜色
}
.underline:last-child:after{ //可以这样用
height:0;
}