JSFiddle - React, Tailwind, and code Playground

HTML

<div id="elm">
    <p>lorem ipsum</p>
</div>

CSS

#elm {display: block;}
#elm p { background:#FF0000; color:#FFFFFF; font-weight:bold;}
#elm p.select{ background:#000099;}

JavaScript

$(document).ready(function(){
    $('#elm').click(function(){ 
          $('body').addClass('diary');
    });
});