FVD Speed Dial - User Style: no search bar, fixed design

gistfile1.css

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

@-moz-document url("about:fvdsddials") {
  /* Hide search bar */
  #searchBar {
    display: none !important;
  }

  /* Bigger group headers, fixed padding */
  #groups_list label {
    font-size: 1.2em !important;
    padding: 8px 15px !important;
  }
  .topMenuLine .group {
    padding: 0px !important;
  }

  /* Less crappy dial border */
  .sd_cell .bottomShadow {
    display: none !important;
  }
  .sd_cell .preview_parent {
    border: solid 1px #bbb !important;
    box-shadow: 2px 2px 3px rgba(0,0,0,0.15);
  }
}

Hello, How to use this?

@jusubzero This code is obsolete and no longer works since Firefox removed XUL, among other things.