CSS伪类实现0.5px边框
div-class为需要添加0.5px边框的元素的类名，下面是less写法，css写法把嵌套的&::after提出来，换成.div-class::after
.div-class {
position: relative;
&::after{
position: absolute;
bottom: 0;
content:'';
width: 100%;
height: 1px;
background-color: #F1F1F1;
transform: scaleY(0.5);
}
}