JSFiddle - React, Tailwind, and code Playground

HTML

<div class="parent">
    <div class="centered-child">
        <p>Lorem ipsum</p>
    </div>
</div>

CSS

.parent
{
    position: relative; /* or whatever you need, just have it set */
    height: 100px;
    width: 500px;
    background: yellow;
}

.centered-child
{
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    width: 50px;
    height: 20px;
    margin: auto;
    background: red;
}