JSFiddle - React, Tailwind, and code Playground

HTML

<a href="http://google.com" class="readmore">Read more</a>

CSS

a {
  color:black;
  padding:10px 20px;
  background-color:#cdcdcd;
  text-decoration:none;
}
a:hover{
  background-color:#000;
  color:white;
}