JSFiddle - React, Tailwind, and code Playground

HTML

<a id="nav-unanswered" href="/unanswered">Unanswered</a>

CSS

#nav-unanswered {
    background-image: url('http://cdn.sstatic.net/gaming/img/sprites-nav.png?v=1');
    background-repeat: no-repeat;
    overflow: hidden;
    background-color: transparent;
    display: block;
    text-indent: -999em;
    height: 24px;
    width: 118px;
    background-position: -340px 0;
}
#nav-unanswered:hover { background-position: -340px -35px }
a, #hmenus li { transition: all 0.25s linear, background-position 0 }