JSFiddle - React, Tailwind, and code Playground

by odinokun

HTML

<div class=grey>
  <div class="black"></div>
</div>

CSS

.grey {
  position: relative;
  width: 200px;
  height: 400px;
  background-color: #ccc;
  margin-top: 100px;
}
.black {
  position: absolute;
  top: -25px;
  left: 0;
  right: 0;
  width: 50px;
  height: 50px;
  background-color: #000;
  margin: auto;
}