JSFiddle - React, Tailwind, and code Playground

HTML

<h1>Test Javascript</h1>
  <p>This is the first para.</p>
  <p>This is the second para.</p>
  <p>This is the third para.</p>
  <p>This is the last para.</p>

JavaScript

$(document).ready(function(){
    $("p").first().css("background-color", "red");
});