JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.0/jquery.min.js"></script>
<div id="back">
  <div id="myDiv"></div>
  <span id="text"></span>
</div>

CSS

#myDiv {
  height: 0px;
  width: 50px;
  background-color: black;
  position: absolute;
}

#back {
  height: 200px;
  width: 200px;
  background-color: teal;
}

JavaScript

$("#mydiv").animate({height: "50px"}, 1000);