JSFiddle - React, Tailwind, and code Playground
HTML
<div id="yes">
<div class="wrapper">
<p>foobar</p>
</div>
</div>
CSS
.newClassName { background-color: yellow; }
JavaScript
$("div#yes > div.wrapper > p").addClass("newClassName");
console.log($("div#yes > div.wrapper > p").html())