JSFiddle - React, Tailwind, and code Playground

HTML

<div id="Container">
    <div id="Nav"></div>
</div>

CSS

#Container {
    width: 500px;
    height: 40px;
    background: #444444;
    overflow: hidden;
}

#Nav {
    width: 200px;
    height: 20px;
    background: #CCCCCC;
    margin-left: auto;
    margin-right: auto;
    margin-top: 10px;
}