@namespace url(http://www.w3.org/1999/xhtml);

@-moz-document domain("youtube.com") {

#instream_google_companion_ad_div {
display: none; 
visibility: hidden;
}

div#watch-sidebar {
margin-top: -449px !important;
}
div#ad_creative_1, div#ad_creative_2, div#ad_creative_3 {
display:none !important;
visibility:hidden !important;
}
div#watch-channel-brand-div {
display:none !important;
visibility:hidden !important;
}
#watch-longform-ad {
display:none !important;
visibility:hidden !important;
}
}