a.back-to-top {	display: none;	width: 60px;	height: 60px;	text-indent: -9999px;	position: fixed;	z-index: 999;	right: 20px;	bottom: 20px;	background: #27AE61 url("up-arrow.png") no-repeat center 43%;	-webkit-border-radius: 30px;	-moz-border-radius: 30px;	border-radius: 30px;}a:hover.back-to-top {	background-color: #339900;}