JSFiddle - React, Tailwind, and code Playground

HTML

<div></div>

CSS

div{
    height: 400px;
    width: 300px;
    margin: 0 auto;
    background: #f2f2f2;
    position: relative;
}
div:after{
    content: '';
    width:300px;
    height: 50px;
    position: absolute;
    top:175px;
    box-shadow: 0 0 30px rgba(0, 0, 0, .3),
                0 50px 30px rgba(0, 0, 0, .25),
                0 -50px 30px rgba(0, 0, 0, .25),
                0 100px 30px rgba(0, 0, 0, .2),
                0 -100px 30px rgba(0, 0, 0, .2),
                0 150px 30px rgba(0, 0, 0, .15),
                0 -150px 30px rgba(0, 0, 0, .15);        
    z-index: -1;
}