JSFiddle - React, Tailwind, and code Playground

HTML

<div class="eins"></div>

CSS

.eins {
  box-shadow: 0px 10px 0px 1px #464646, 0px 16px 0px 1px #464646, 0px 22px 0px 1px #464646;
  width: 16px;
  height: 0px;
}