1 父类设置
position:relative
2 子类设置
position: absolute;
left:0;
top:-1px;
content: "";
display: inline-block;
100%;
height:1px;
border-bottom:1px solid red;
transform: scaleY(0.5);
1 父类设置
position:relative
2 子类设置
position: absolute;
left:0;
top:-1px;
content: "";
display: inline-block;
100%;
height:1px;
border-bottom:1px solid red;
transform: scaleY(0.5);