#backtotop{background:0 0;width:72px;height:72px;opacity:.4;right:20px;bottom:20px;position:fixed;cursor:pointer;border:2px solid transparent}#backtotop:hover{opacity:1}.btt-background{position:relative;display:block;width:100%;height:100%;background:#3094b5}#backtotop:before{position:absolute;display:block;content:"";width:34px;height:25px;z-index:2;background:url(../images/layout/arrow_BtT.png) no-repeat;top:50%;left:50%;transform:translate(-50%,-50%);-ms-transform:translate(-50%,-50%);-webkit-transform:translate(-50%,-50%);-o-transform:translate(-50%,-50%)}@media only screen and (max-width:719px){#backtotop{width:43px;height:43px}#backtotop:before{width:21px;height:15px;background:url(../images/layout/arrow_BtT_small.png) no-repeat}}