/* Reveal */ .reveal() { @duration: @fastDuration; .hacks(); position: relative; overflow: hidden; &:before { content: ""; position: absolute; z-index: -1; left: 0; right: 0; top: 0; bottom: 0; border-color: @activeColor; border-style: solid; border-width: 0; .prefixed(transition-property, border-width); .prefixed(transition-duration, @duration); .prefixed(transition-timing-function, ease-out); } &:hover, &:focus, &:active { &:before { .prefixed(transform, translateY(0)); border-width: 4px; } } }