#back-top{position:fixed;bottom:105px;margin-left:-265px;z-index:1000;}
#back-top a{width:68px;display:block;text-align:center;font:11px/100% Arial, Helvetica, sans-serif;text-transform:uppercase;text-decoration:none;color:#bbb;border:none;-webkit-transition:1s;-moz-transition:1s;transition:1s; margin-bottom: 45px; }
#back-top a:hover{color:#000;}
#back-top span{width:68px;height:62px;display:block;margin-bottom:0;background:transparent url(../images/up-arrow.png) no-repeat center center;-webkit-border-radius:15px;-moz-border-radius:15px;border-radius:15px;-webkit-transition:1s;-moz-transition:1s;transition:1s;}
#back-top a:hover span{background-color:transparent;}
#back-top a.top span{background:transparent url(../images/up-arrow.png) no-repeat center center;}
#back-top a.bottom span{background:transparent url(../images/down-arrow.png) no-repeat center center;}