JSFiddle - React, Tailwind, and code Playground

HTML

<body>
  <div class="one">
    <div class="two">
     <div class="three">
      ...
        <div class="region">

        </div>
        <button id="clickme">
         here
        </button>
     </div>
     
    </div>
  </div>
</body>

CSS

html
{
  height: 100%;
}

body
{
  height: 100%;
}

.one
{
  min-height: 100%;
  height:1px;
  background: green;
}

.two
{
  height: 100%;
}
.three{
  
}
.region{
  height:200px;
  border:1px solid red;
   background: green;
}

JavaScript

$(document).ready(function(){
	$("#clickme").click(function(){
  		$(".two").append("<div class='region'></div>")
  });
})