JSFiddle - React, Tailwind, and code Playground

HTML

<html>
    <head>
    </head>            
    <body>
        <div id="container">
            <div id="content">
                <h1>Centered div</h1>
            </div>
        </div>
    </body>
</html>

CSS

#container{
   position: absolute;
   top: 50%;
   margin-top: -200px;/* half of #content height*/
   left: 0;
   width: 100%;
}
#content {
   width: 624px;
   margin-left: auto;
   margin-right: auto;
   height: 395px;
   border: 1px solid #000000;
}