JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
    <p>I'm vertically/horizontally centered!</p>
</div>

CSS

html, body, .container {
    height: 100%;
}
.container {
    position: relative;
    text-align: center;
}
.container > p {
    position: absolute;
    top: 50%;
    left: 0;
    right: 0;
    margin-top: -9px;
}