JSFiddle - React, Tailwind, and code Playground

HTML

<div id = "master_wrapper">
<div id = "header">
	Header
</div>
</div>

CSS

body, html {
    margin: 0;
    height: 100%;
}

#master_wrapper {
    width: 58px;
    height: 58px;
    background: #57a957;
    padding: 4%;
}

#header {
    background: red;
    width: 100%;
    height: 100%;
}