JSFiddle - React, Tailwind, and code Playground

HTML

<div id="wrapper">
    <section id="sidebar">
        <p>Some sidebar content</p>
    </section>
    <section id="content">
        <p>Some content</p>
    </section>
</div>

CSS

html, body {
    height: 100%;
}

#wrapper {
    min-height: 100%;
}

#sidebar, #content {
    float: left;
    height: 100%;
}

#sidebar {
    background: grey;
}

#content {
    background: red;
}