JSFiddle - React, Tailwind, and code Playground

HTML

<div id="container">
    <diV id="menu">
    </div>
</div>

CSS

html, body {
    height:100%;
    width:100%;
    margin:0;
}
#container {
    width: 1300px;
    background-color:green;
    margin:0 auto;
    overflow:hidden;
}
#menu {
    float:left;
    width:20%;
    background-color: yellow;
    height:50px;
}