JSFiddle - React, Tailwind, and code Playground

HTML

<div id="top-feature">
    <div id="slideshow">
    </div>
    <div id="promo">
    </div>
</div>

CSS

#top-feature {
    background: red;
    height: 320px;
    width: 897px;
}

#top-feature div {
    float: left;
}

#slideshow {
    height: 300px;
    width: 548px;
    background: blue;
}

#promo {
    background: green;
    height: 100px;
    width: 200px;
}