.btn-to-up {
	position: fixed;
	bottom: 60px;
	right: 5%;
	display: flex;
	align-items: center;
	justify-content: center;
	width: 80px;
	height: 80px;
	border-radius: 5px;
	border: 1px solid #F4F4F4;
	background: #fff;
	cursor: pointer;
	opacity: 0;
	visibility: hidden;
	transition: background-color .2s, visibility .2s, opacity .2s;
	z-index: 20;
}
.btn-to-up.visible{
	visibility: visible;
	opacity: 1;
}
.btn-to-up:hover{
	background: #f2f2f2;
}