JSFiddle - React, Tailwind, and code Playground

by Ivanq

HTML

<div class="rect"></div>

CSS

.rect {
  display: inline-block;
  width: 100px;
  height: 50px;
  background: red;
  margin-left: 25px;
  position: relative;
}
.rect:before {
  display: inline-block;
  width: 0;
  height: 0;
  border-top: 25px solid transparent;
  border-right: 25px solid red;
  border-bottom: 25px solid transparent;
  position: absolute;
  top: 0;
  left: -25px;
  content: "";
}
.rect:after {
  display: inline-block;
  width: 0;
  height: 0;
  border-top: 25px solid transparent;
  border-left: 25px solid red;
  border-bottom: 25px solid transparent;
  position: absolute;
  top: 0;
  right: -25px;
  content: "";
}