JSFiddle - React, Tailwind, and code Playground

HTML

<div class='outer'>
    <div class='middle'>
        <div class='inner'>
            Text should be centered
        </div>
    </div>
</div>

CSS

.outer {
    position: absolute;
    left: 200px;
    top: 50px;
    width: 100px;
    height: 100px;
    border: 2px solid #00f;
    border-radius: 10px;
}

.middle {
    position: absolute;
    left: 50%;
    top: 50%;
    line-height: 1em;
}

.inner {
    position: relative;
    left: -50%;
    top: -50%;
    width: 5em;
}