JSFiddle - React, Tailwind, and code Playground

HTML

<div id="header">
        <h2>Hi</h2>
    </div>

CSS

#header {
    background-color: green;
    position: relative;
    top: 5px;

    border: 2px solid black;
}

h2 {
    text-align: center;
    font-size: 100px;
    margin: 0;
}