JSFiddle - React, Tailwind, and code Playground

HTML

<div></div>

CSS

div {
  width: 300px;
  height: 100px;
  margin-left: 50px;
  border: 1px solid #000;
}

div {
  box-shadow: 2px 0px 0px darkred,
             -2px 0px 0px darkred;
}