JSFiddle - React, Tailwind, and code Playground

HTML

<div>

CSS

body {
    background-color: #666;
}

div {
    width: 100px;
    height: 100px;
    border: 40px solid rgba(0,0,0,.2);
    margin: 20px;
    background-color: #fff;
    border-radius: 8px;

}