JSFiddle - React, Tailwind, and code Playground

HTML

<header>
    </header>
<div id="wrapper">
   
</div>

CSS

#wrapper{
    width: 500px;
    height: 400px;
    background: red;
    margin: 0 auto;
}
header{
    width: 100%;
    height: 50px;
    background: blue;
}