JSFiddle - React, Tailwind, and code Playground

by web tiki

HTML

<div>content</div>

CSS

html,body{
    height:100%;
    margin:0;
    padding:0;
    background: url('http://lorempixel.com/output/people-q-c-640-480-1.jpg');
    background-size:cover;
}
div {
    background:none;
    height:50%;
    position:relative;
    overflow:hidden;
    z-index:1;
}
div:after {
    content:'';
    position:absolute;
    left:-600%;
    width:1300%;
    padding-bottom:1300%;
    top:80%;
    background:none;
    border-radius:50%;
    box-shadow: 0px 0px 0px 9999px teal;
    z-index:-1;
}