JSFiddle - React, Tailwind, and code Playground

HTML

<div id="outer"><div id="inner"></div></div>

CSS

* {
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
}

#inner {
  background: green;
  width: 100%;    
  height: 100px;
}

#outer {
  position: relative;
  background: black;
  width: 200px;
  -webkit-transition-property: padding-left;
  -moz-transition-property: padding-left;
  -webkit-transition-duration: 0.25s;
  -moz-transition-duration: 0.25s;
  padding-left: 100px;
}

#outer:hover {
  padding-left: 0;        
}