JSFiddle - React, Tailwind, and code Playground

HTML

<main>
    <aside>Menu</aside>
    <section>
        <article>Content</article>
    </section>
</main>

CSS

html {
    background-color:black;
}
main {
    background-color:red;
    width:85%;
    height:400px;
    margin: 0 auto;
    padding:4px;
}
aside {
    width:20%;
    height:90%;
    margin-top:5%;
    background-color:blue;
    color:white;
    clear:left;
    display:inline-block;
}
section {
    display:inline-block;
    background-color:green;
    padding:4px;
}
article {
    background-color:#F00;
}