#back-to-top {
    background-color:white;
    bottom: 0;
    box-shadow: 0 0 6px ;
    color: #444444;
    padding: 2px 2px;
    position: fixed;
    right: 20px;
    cursor: pointer;
}

body{
    background-image:url("https://images.cnblogs.com/cnblogs_com/yhq123/1507792/o_u=583523211,2601846513_fm=26_gp=0.jpg") !important;
    background-repeat: no-repeat; 
    background-size:cover;
    background-position:center top;
    background-attachment: fixed
}
#home{
    opacity:0.9;
}
.postBody{
    font-size:16px
}