JSFiddle - React, Tailwind, and code Playground

HTML

<button><span class="text">X</span></button>

CSS

button
{
    display: block;
    padding: 0px;
    margin: 0;
    width: 19px;
    height: 19px;
    border: 1px solid #000;
    border-radius: 5px;
}

button span.text {
    font-size: 11px;
    padding: 2px;
}