#backTop{width:30px;height:30px;padding:10px;border-radius:4px;text-indent:-9999px;cursor:pointer;z-index:999999999;display:none;box-sizing:content-box;-webkit-box-sizing:content-box}#backTop.black{background:url(../images/uparr-48-w.png) no-repeat center center rgba(23,154,214,0.5);border:1px solid #fff}#backTop.red{background:url(../images/uparr-48-w.png) no-repeat center center rgba(217,97,81,0.9);border:1px solid #fff}#backTop.blue{background:url(../images/uparr-48-w.png) no-repeat center center rgba(23,154,214,0.9);border:1px solid #fff}#backTop:hover{background:url(../images/uparr-48-w.png) no-repeat center center rgba(23,154,214,0.9)}