.bck {
	position: fixed;
	bottom: 1rem;
	right: 1rem;
	background: #2392ec;
	border-radius: 60px;
	color: #fff;
	visibility: hidden;
	width: 60px;
	height: 60px;
	line-height: 50px;
	z-index:2000;
	text-align: center;
	transition-property: all;
}

.bck.bck-on {visibility: visible;}

/*.fade{opacity: 0;}*/

.bck-on.fade{opacity: 1;}

.rightToLeft {right : -50px;}

.bck-on.rightToLeft{right: 1rem;}

.bottomToTop {bottom: -50px;}

.bck-on.bottomToTop {bottom:1rem;}

.bck-leftToRight {left: -50px;}

.bck-on.leftToRight {left:1rem;}

.topToBottom {top: -50px;}

.bck-on.topToBottom {top:1rem;}