body {
    background-image:url(https://images2015.cnblogs.com/blog/1018686/201611/1018686-20161116155332810-1494305008.jpg
);
    background-attachment:fixed;

    filter:alpha(opacity=87);
    -moz-opacity:0.83;
    -khtml-opacity: 0.85;
    opacity: 0.8;
}
#site_nav_under {
    display: none;
}
.c_ad_block, .ad_text_commentbox {
    display: none;
    margin: 0;
    padding: 0;
}
#ad_under_google {
    height: 0;
    overflow: hidden;
}
#ad_under_google a {
    display: none;
}