vue 1px边框

border-1px($color) position: relative &:after
display: block
position: absolute
left: 0;
bottom: 0;
width: 100%;
border-top: 1px solid $color;
content: ’ ’

border-none() &:after
display: none

引用时候：border-1px(rgba(7, 17, 27, .1))