JSFiddle - React, Tailwind, and code Playground

HTML

<div class="wrapper">
		<div class="shadow"></div>
		<div class="content">This is your content</div>
	</div>

CSS

* {
    margin: 0;
    padding: 0;
    border: 0;
    box-sizing: border-box;
}

.wrapper {
    position: relative;
    margin: 100px auto 0;
    width: 80%; 		/* .content width */
    height: 400px; 		/* .content height */
}

.content {
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    background: #fff;	/* .content background */
}

.shadow {
    position: absolute;
    top: -10%; 			/* .content shadow top height */
    right: -5%; 		/* .content shadow right width */
    bottom: -10%; 		/* .content shadow bottom height */
    left: -5%; 			/* .content shadow left width */
    background: #000; 	/* .content shadow, unfortuntely no blur effect */
}