#ns_basetheme_back_to_top{position:fixed;bottom:40px;right:40px;z-index:9999;width:32px;height:32px;text-align:center;line-height:30px;background:#f5f5f5;color:#444;cursor:pointer;border:0;border-radius:2px;text-decoration:none;transition:opacity 0.2s ease-out;opacity:0;}#ns_basetheme_back_to_top:hover{background:#e9ebec;}#ns_basetheme_back_to_top.show{opacity:1;}#content{height:2000px;}