JSFiddle - React, Tailwind, and code Playground

HTML

<h1>This is my site</h1>
<h2 class="important">Here are some things I like</h2>
<ul>
    <li id="cats">Cats</li>
    <li>The Internet</li>
    <li>Food</li>
</ul>

CSS

li {color: red;}

.important {color: blue;}

#cats {color: green;}

JavaScript

$("#cats").click(function(){
  alert('you clicked cats');
});