JSFiddle - React, Tailwind, and code Playground

HTML

<div>
    <div class="a">1a</div>
    <div class="a">2a</div>
    <div class="a">3a</div>
    <div class="b">1b</div>
    <div class="b">2b</div>
    <div class="a">4a</div>
</div>

CSS

div > div:nth-child(5){
    color:#d40000;
}