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

@-moz-document url-prefix("http://www.nicovideo.jp/") {
  #PAGEBODY .g1_bg > table > tbody > tr > td > div {
    display: none !important;
  }
}

@-moz-document url-prefix("http://live.nicovideo.jp/") {
  .pcounter_over {
    display: none !important;
  }
}