diff -r 000000000000 -r 6474c204b198 toolkit/themes/linux/global/inContentUI.css
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/themes/linux/global/inContentUI.css	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,34 @@
+/* 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/. */
+
+/*
+ * The default namespace for this file is XUL. Be sure to prefix rules that
+ * are applicable to both XUL and HTML with '*|'.
+ */
+@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul");
+@namespace html url("http://www.w3.org/1999/xhtml");
+
+/* Page background */
+*|*:root {
+  -moz-appearance: none;
+  padding: 18px;
+  background-color: Window;
+  background-image: /* Texture */
+                    url("chrome://global/skin/inContentUI/background-texture.png");
+  color: WindowText;
+}
+
+html|html {
+  font: message-box;
+}
+
+/* Content */
+*|*.main-content {
+  /* Needed to allow the radius to clip the inner content, see bug 595656 */
+  overflow: hidden;
+  background-color: -moz-Field;
+  color: -moz-FieldText;
+  border: 1px solid ThreeDShadow;
+  border-radius: 5px;
+}