JSFiddle - React, Tailwind, and code Playground

HTML

<div class="divOne">
        <div class="divTwo"></div>
    </div>

CSS

.divOne {
        width: 80%;
        height: 250px;
        background: #00ff00;
    }

    .divTwo {
        width: 100%;
        height: 150px;
        background: #000;
    }