JSFiddle - React, Tailwind, and code Playground

HTML

<div id="orangeBox">
    <span id="x">X</span>
</div>

CSS

#orangeBox {
    background: #f90;
    color: #fff;
    font-family: 'Helvetica', 'Arial', sans-serif;
    font-size: 2em;
    font-weight: bold;
    text-align: center;
    width: 40px;
    height: 40px;
    border-radius: 5px;
}