JSFiddle - React, Tailwind, and code Playground

HTML

<div id="a"><div id="b">B</div></div>
<div id="a"><div id="c">C</div></div>

CSS

#a { height: 400px; border: 1px solid red;  }
#b { height: 200px; }
#a :contains #b { height: 300px; border: 1px solid blue; }