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

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

#chrome-link, .user-info, #subscribeDiv, #upload-button, #watch-this-vid-info, #footer, #copyright, #ad300x250, #google_companion_ad_div, #watch-channel-brand-div, #watch-channel-brand-cap, #watch-more-popular, #watch-promoted-videos-container, #search-pva {display:none !important;}

}