JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
    <div class="content">
        <h1>Conteúdo</h1>
        <p>Subtítulo</p>
    </div>
</div>

CSS

.container {
    position: absolute;
    width: 100%;
    height: 100%;
    background: #ccc;
}

.content {
    position: absolute;
    top: 50%;
    left: 25%;
    width: 50%;
    text-align: center;
    -webkit-transform: translateY( -50% );
    -moz-transform: translateY( -50% );
    transform: translateY( -50% );
}