JSFiddle - React, Tailwind, and code Playground

by kiarash

HTML

<div id="demo"></div>

CSS

#demo {
    background-color: #333;
    height: 100px;
    position: relative;
    width: 100px;
}

#demo:after {
    content: ' '; 
    height: 0; 
    position: absolute; 
    width: 0; 
    border: 10px solid transparent;
    border-top-color: #333; 
    top: 100%; 
    left: 10px; 
}