JSFiddle - React, Tailwind, and code Playground

HTML

<div class="menu">
    menu<br />
    menu<br />
    menu
</div>
<div class="contents">
    contents<br />
    contents<br />
    contents<br />
    contents
</div>

CSS

.menu {
    background: blue;
    color: yellow;
    width: 100px;
    float: left;
}
.contents {
    background: green;
    margin-left: 100px;
}