body {
	background:green;
	padding:0;
	margin:0;
}
.cover {
	width:100vw;
	height:100vh;
	background-image:url("https://picsum.photos/id/545/800/600");
	background-size:100vw 100vh;
	filter:grayscale(1);
	overflow:hidden;
}
.cursor {
	top:0;
	left:0;
	position:absolute;
	height:300px;
	width:300px;
	border-radius:50%;
	background:url("https://picsum.photos/id/545/800/600");
	background-attachment:fixed;
	background-size:100vw 100vh;
	border:1px dashed;
}