JSFiddle - React, Tailwind, and code Playground

by Zikes

HTML

<div class="fancy-shadow" id="box">
    <br /><br /><br /><br /><br /><br />
</div>

CSS

#box{
    margin: 50px;
    background: #a66;
}

.fancy-shadow{position:relative;}
.fancy-shadow:before{
    position: absolute;
    z-index: -2;
    content: "";
    left: 0;
    right: 0;
    top: 10%;
    bottom: 10%;
                            
    border-radius: 10px / 100px;
    box-shadow: 0 0 30px rgba(0, 0, 0, 0.6);
}