JSFiddle - React, Tailwind, and code Playground

HTML

<div>
    <h1>heading</h1>
  <p>foo</p>
  <p>bar</p>
</div>

<div>
<h1>heading</h1>
  <p>foo</p>
  <p>bar</p>
  <p>foo</p>
  <p>bar</p>
</div>

CSS

div p:last-child  {
  color:red;
}