@import './mixins/hairline'; [class*='van-hairline'] { position: relative; &::after { .hairline(); } } .van-hairline { &--top::after { border-top-width: 1px; } &--left::after { border-left-width: 1px; } &--right::after { border-right-width: 1px; } &--bottom::after { border-bottom-width: 1px; } &--top-bottom::after { border-width: 1px 0; } &--surround::after { border-width: 1px; } }