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

@-moz-document domain("search.live.com"), domain("search.msn.co.jp"), 
domain("www.bing.com") {
  body {
    counter-reset: result !important;
  }
  div#results h3:before {
    content: counter(result) ". " !important;
    counter-increment: result !important;
    color: #000 !important;
  }
}