body{
    background-image: url(https://www.bizhiku.net/uploads/allimg/2019/0103/ppe1slbvek2.png); 
    background-repeat:no-repeat;
    background-size:100% 100%;
    -moz-background-size:100% 100%;
}

#navigator{
    opacity:0.5;
}


#mainContent{
    

}