JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
    <div class="block">Hello, world!</div>
</div>

CSS

html, body, .container {
    margin: 0;
    height: 100%;
}

.container {
    text-align: center;
}

.container:before {
    content: '';
    width: 0;
    height: 100%;
    display: inline-block;
    vertical-align: middle;
}

.block {
    display: inline-block;
    font: 48px/1.4 Arial, sans-serif;
    color: #446EA7;
}