.hairline-common() { content: ' '; position: absolute; pointer-events: none; box-sizing: border-box; } .hairline(@border-color: #ebedf0) { .hairline-common(); top: -50%; left: -50%; right: -50%; bottom: -50%; transform: scale(0.5); border: 0 solid @border-color; } .hairline-bottom(@border-color: #ebedf0, @left: 0) { .hairline-common(); left: @left; right: 0; bottom: 0; transform: scaleY(0.5); border-bottom: 1px solid @border-color; }