JSFiddle - React, Tailwind, and code Playground

HTML

<div id="container">
  <article class="copy">copy 1</article>
  <div class="banner">banner 1</div>
  <article class="copy">copy 1</article>
  <div class="banner">banner 2</div>
  <article class="copy">copy 1</article>
  <div class="banner">banner 3</div>
  <div class="banner">banner 4</div>
</div>

CSS

.banner:nth-of-type(1) {background-color:red;}
.banner:nth-of-type(2) {background-color:blue;}