JSFiddle - React, Tailwind, and code Playground

HTML

<div id="outer">
  
    <div id="inner"></div>

    </div>

CSS

#outer {
    width: 100px;
    height: 100px;
    background-color: red;
    }

    #inner {
    width: 50%;  
    height: 200%; 
    background-color: green;
    }