JSFiddle - React, Tailwind, and code Playground

HTML

<nav>
    <ul>
        <li>Item 1</li>
        <li>Item 2</li>
        <li>Item 3</li>
        <li>Item 4</li>
        <li>Item 5</li>
    </ul>
</nav>
<article>
    <div></div>
</article>

CSS

html, body, nav, article {height: 100%;margin: 0;}
nav {overflow: auto;float: left;width: 200px;background: #69A6B9;}
article {overflow: auto;background: #CECCCD;}

/* Pour l'exemple */
nav ul {background: #DAB159;}
nav li {padding: 100px 0;}
article div {height: 2000px;}