JSFiddle - React, Tailwind, and code Playground

HTML

<html>
<body>
<div class="outer">
<div class="inner"></div>
</div>
</body>
</html>

CSS

body {
  background: #999;
}
.outer {
  background: white;
  border: 2px dashed #000;
  display: inline-block;
}
.inner {
  width: 200px;
  height: 100px;
  background: #999;
}