JSFiddle - React, Tailwind, and code Playground

HTML

<a class="underline" href="#">underline</a>
<a class="border" href="#">border</a>

CSS

a{
    font-size: 2em;
    font-family: Arial, sans-serif;
    margin-right: 1em;
}

a:link{
    color: #000;
    text-decoration: none;
}

.underline:hover{
    text-decoration: underline;
}

.border:hover{
    border-bottom: 2px solid #000;
    padding-bottom: -8px;
}