JSFiddle - React, Tailwind, and code Playground

HTML

<a href="#" class="thumbnail">test</a>
<a href="#" class="thumbnail">test</a>
<a href="#" class="thumbnail">test</a>
<a href="#" class="thumbnail">test</a>
<a href="#" class="thumbnail">test</a>
<a href="#" class="thumbnail">test</a>
<a href="#" class="thumbnail">test</a>

CSS

a.thumbnail:hover,
a.thumbnail:focus,
a.thumbnail.active
 {
  border-color: gray;
  color:red;
  background-color:#ADDEA
}

JavaScript

$('a.thumbnail').click(function(){
    
    $('a.thumbnail').removeClass('active');
    
    $(this).addClass('active');
    
});