.link-underline{border-bottom-width:0;background-size:0 3px;background-position:0 100%;background-repeat:no-repeat;transition:background-size .5s ease-in-out}.link-underline,.link-underline-black{background-image:linear-gradient(transparent,transparent),linear-gradient(#fff,#fff)}.link-underline:hover{background-size:100% 3px;background-position:0 100%}