body{
  background:url('https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1564402955327&di=3bd941cb53a2be1e73a7ec87008c3d55&imgtype=0&src=http%3A%2F%2Fmmbiz.qpic.cn%2Fmmbiz_gif%2Fl9qY3aVN7se1Ygsvts8QOPTZjtU49vx8tgSBBqJL0iahJmR340MJY1p8ibVcYfYibFqsUAhjd7JnESMia9gSJGz8Mg%2F640%3Fwx_fmt%3Dgif') fixed center no-repeat ;
}
#navigator{
 background-color:rgba(125,125,125,0.7);
}
#main{
  background-color:rgba(255,255,255,0.5);
}
#mainContent{
  background-color:rgba(255,255,255,0.7);
}
#back-top {
    position: fixed;
    bottom: 10px;
    right: 5px;
    z-index: 200;
}
#back-top span {
    width: 50px;
    height: 64px;
    display: block;
    background: url('https://www.cnblogs.com/images/cnblogs_com/yinfa/1514668/t_top.png') no-repeat center center;
}
.catListTitle{
  display:none;
}
.cat{
    text-align: left;
    padding: 5px 10px;
    border: 1px solid #ccc;
    background: #f0f0f0;
}