JSFiddle - React, Tailwind, and code Playground

HTML

<a href="#uno">uno</a>
<a href="#dos">dos</a>
<a href="#tres">tres</a>
<ul>
  <li id="uno">1</li>
  <li id="dos">2</li>
  <li id="tres">3</li>
</ul>

CSS

li:target{
  background: royalblue;
  color: white;
}
li{
  list-style: none;
  width: 20px;
  height: 20px;
  background: white;
  color: black;
  font-family: sans-serif;
  transition: .3s;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 20px;
}