palemoon-dev/palemoon/components/statusbar/content/prefs.css

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

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

.css-bg-editor {
  -moz-binding: url("chrome://browser/content/statusbar/prefs.xml#css-bg-editor");
}