Firefox style

@namespace url(http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul);

#PopupAutoCompleteRichResult  {
  background: rgba(0, 0, 0, 0.2) !important;
  border: 0;
}
#PopupAutoCompleteRichResult .autocomplete-richlistbox{
  background: transparent;
}
#PopupAutoCompleteRichResult .ac-title-box .ac-normal-text,
#PopupAutoCompleteRichResult .ac-url-text {
  padding-left: 0.5em;
  padding-right: 0.5em;
  background: rgba(255, 255, 255, 1) !important;
  border-radius: 0.5em;
}

Daum Calendar

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

@-moz-document domain("cal.daum.net") {
  #mv_container {
    font-family: "NanumBarunGoehic", sans-serif;
  }
}

RigVeda Wiki

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

@-moz-document domain("rigvedawiki.net") {
  /* main content font and font size */
  #wikiBody {
    font-size: 1.4em !important;
    font-family: "NanumBarunGothic", sans-serif;
    line-height: 1.6em;
  }

  /* footnote number and footnotes list */
  tt.foot {
    font-size: 0.8em !important;
    vertical-align: bottom !important;
    position: relative;
    bottom: 1ex;
  }

  .foot tt.foot {
    font-size: 1em !important;
    vertical-align: bottom;
    bottom: 0;
  }
}