suite/themes/modern/communicator/sidebar/preview.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/. */

/* ===== preview.css ====================================================
  == Styles used by the Sidebar Preview dialog.
  ======================================================================= */

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

#previewframe {
  margin: 0px;
  border: none;
  width: 162px;
  height: 300px;
  min-width: 10px;
  min-height: 1px;
}