.box2 {
	width:100vw;
	height:100vh;
	background-color:#000;
	position:fixed;
	left:0;
	top:0;
	transition:all .6s;
	z-index:-1;
}
.box {
	width:200px;
	height:200px;
	position:absolute;
	left:0;
	right:0;
	top:0;
	bottom:0;
	margin:auto;
}
.btn {
	cursor:pointer;
	width:140px;
	height:60px;
	background-color:rgba(224,222,222,.8);
	border:1px solid rgb(239,237,237);
	color:#fff;
	font-size:22px;
	border-radius:60px;
	box-shadow:0 10px 2px 0 #ccc,0 10px 8px 0px rgb(248,246,246) inset,0 0 6px 0px #ccc inset;
}
.btn:active {
	margin-top:2px;
	box-shadow:0 8px 2px 0 #ccc,0 10px 8px 0px rgb(248,246,246) inset,0 0 10px 0px #ccc inset;
}
.btn:active+.box2 {
	opacity:0;
}