JSFiddle - React, Tailwind, and code Playground

HTML

<div id="parent">
    <div id="child">
        I'm as wide as my papa will let me get<br />
        without getting in the way of his padding.
    </div>
</div>

CSS

#parent {
    background-color: #000;
    padding: 5px;
}

#child {
    padding: 5px;
    background-color: #00f;
    color: #fff;
}