JSFiddle - React, Tailwind, and code Playground

HTML

<div style="background:blue" id="containerDiv">
  <div style="background:red; height:200px;width:200px;" id="innerDiv">
  
  </div>
</div>

CSS

html, body {
    width: 210mm;
    height: 107mm;
    padding:0 !important;
    margin:0 !important;
    overflow:hidden;
    border:1px solid black;
    }
    #containerDiv{
        margin:50% auto;
        }