#chat_window .chat_box .menu #go_top {background-image: url(//ueeshop.ly200-cdn.com/u_file/UPBA/UPBA565/2601/20/photo/topback.jpg);background-position: center !important;background-size: 80px auto;width: 80px;height: 80px;}
    @media screen and (max-width: 1000px) {
        #chat_window .chat_box .menu #go_top {background-size: 60px auto;width: 60px;height: 60px;}
    }