JSFiddle - React, Tailwind, and code Playground

HTML

<section class="flex-container">    
    Hello Flexbox! 
</section>

CSS

html, body{ color: white; font: 20px/1.1em Calibri; }
.flex-container{
    display: flex; justify-content: center; align-items: center; height: 350px;
    background: LightSeaGreen; 
}