JSFiddle - React, Tailwind, and code Playground

HTML

<div style="position: absolute; height: 400px; border:1px solid;">
    <div class="textBox">Vertically Aligned DIV</div>
</div>

CSS

/* allows vertical alignment */
.textBox {
    margin: auto;
    position: absolute;
    top: 0;
    left: 0;
    bottom: 0;
    right: 0;
    display: table;
}