<div class="container"></div>

body {
	background: url(https://images.unsplash.com/photo-1544306094-e2dcf9479da3) no-repeat;
	background-size: cover;
	display: grid;
	align-items: center;
	justify-content: center;
	height: 100vh;
}

.container {
	width: 30rem;
	height: 20rem;
	box-shadow: 0 0 1rem 0 rgba(0, 0, 0, .2);	
	border-radius: 5px;
	background-color: rgba(255, 255, 255, .15);
	
	backdrop-filter: blur(5px);
}