JSFiddle - React, Tailwind, and code Playground

HTML

<div class="cls1">
  <div class="cls2">
    <p>123</p>
    <p>123</p>
    <p>123</p>
  </div>
  <div class="cls2">
    <p>123</p>
    <p>red</p>
    <p>123</p>
  </div>
  <div class="cls2">
    <p>123</p>
    <p>123</p>
    <p>123</p>
  </div>
</div>

CSS

.cls2:nth-child(2) p:nth-child(2) {
    color: red;
}

JavaScript

var num_block = $('.cls2').eq(1).css('background-color','green');
$(num_block).find("p").eq(1).css('color','#ffffff');