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

@-moz-document url-prefix("http://www.nicovideo.jp/tag/") {
  #PAGEBODY > .content_672 > div[style*="width:640px;"] ~ p.font12,
  #PAGEBODY > .content_672 > div[style*="width: 640px;"] ~ p.font12,
  #PAGEBODY > .content_672 > div[style*="width:640px;"] ~ div[id^="item"],
  #PAGEBODY > .content_672 > div[style*="width: 640px;"] ~ div[id^="item"] {
    display: none !important;
  }
}