JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
  <div class="first">
  
  </div>
</div>

CSS

.container {
  margin: 0 auto;
  background-color: green;
  width: 100px;
  height: 300px;
}

.first {
  background-color: orange;
  width: 100%;
  height: 100px;
  position: absolute;
  left: 0;
  /*top: 100px;*/
}