JSFiddle - React, Tailwind, and code Playground

HTML

<div class="div1">
  <div class="div3">1</div>
  <div class="div2">
    <div class="div3">2</div>
  </div>
  <div class="div4">
    <div class="div3">3</div>
  </div>
</div>

CSS

.div1 .div3 {
  background-color: red;
}

.div1 > .div3 {
  background-color: blue;
}