[gnome-themes-standard] header-bar: add a first basic theming for header bar widgets

[Cosimo Cecchi <cosimoc src gnome org>]

commit ce04054e8f76da744c75479f7ffa61b5489c396f
Author: Cosimo Cecchi <cosimoc gnome org>
Date:   Mon Feb 18 12:54:44 2013 -0500

    header-bar: add a first basic theming for header bar widgets
    
    As used by the control center.
    For now, just render a stroke at the bottom.

 themes/Adwaita/gtk-3.0/gtk-widgets.css |   19 +++++++++++++++++++
 1 files changed, 19 insertions(+), 0 deletions(-)
---
diff --git a/themes/Adwaita/gtk-3.0/gtk-widgets.css b/themes/Adwaita/gtk-3.0/gtk-widgets.css
index 05731b0..f821350 100644
--- a/themes/Adwaita/gtk-3.0/gtk-widgets.css
+++ b/themes/Adwaita/gtk-3.0/gtk-widgets.css
@@ -2510,6 +2510,25 @@ GtkCheckButton:selected:focus {
 
 }
 
+/***************
+ * Header bars *
+ ***************/
+.header-bar {
+    border-width: 0 0 2px;
+    border-style: solid;
+    border-image: linear-gradient(to top,
+                                  shade(@borders, 0.90),
+                                  shade(@borders, 0.90) 1px,
+                                  alpha(black, 0.07) 1px) 0 0 2;
+}
+
+.header-bar:backdrop {
+    border-image: linear-gradient(to top,
+                                  @unfocused_borders,
+                                  @unfocused_borders 1px,
+                                  transparent 1px) 0 0 2;
+}
+
 /********************
  * Primary Toolbars *
  ********************/