[gnome-builder] style: fix header.notebook styling for gtk 3.19

[Christian Hergert <chergert src gnome org>]

commit d7ce54c73a0776e63ae29e2cd6ee8145c5d96e98
Author: Christian Hergert <chergert redhat com>
Date:   Wed Oct 28 13:57:16 2015 -0700

    style: fix header.notebook styling for gtk 3.19
    
    This seems to have broke during 3.19 development, so let's be a bit more
    precise with our css settings.

 data/theme/Adwaita-shared.css |   12 +++++++++---
 1 files changed, 9 insertions(+), 3 deletions(-)
---
diff --git a/data/theme/Adwaita-shared.css b/data/theme/Adwaita-shared.css
index 494135d..51f62cf 100644
--- a/data/theme/Adwaita-shared.css
+++ b/data/theme/Adwaita-shared.css
@@ -32,11 +32,17 @@ GbEditorTweakWidget GtkScrolledWindow {
 /*
  * View stack styling.
  */
-GbViewStack GtkBox.header.notebook {
+GbViewStack > GtkBox.vertical > GtkBox.header.notebook {
+  background-color: shade (@theme_bg_color, 0.95);
   border-bottom: 1px solid @borders;
 }
-GbViewStack:not(.focused) GtkBox.header.notebook {
-  background-color: shade (@theme_bg_color, 0.95);
+GbViewStack.focused > GtkBox.vertical > GtkBox.header.notebook,
+GbViewStack.backdrop.focused > GtkBox.vetical > GtkBox.header.notebook {
+    background-color: shade (@theme_bg_color, 0.90);
+}
+GbWorkspacePane.focused > GtkBox.vertical > GtkBox.horizontal.notebook.header,
+GbWorkspacePane.focused > GtkBox.vertical > GtkBox.horizontal.notebook.header.backdrop {
+    background-color: shade (@theme_bg_color, 0.90);
 }
 GbViewStack > GtkBox.vertical > GtkBox.header.notebook.horizontal > GtkEventBox > GtkBox.horizontal > 
.button,
 GbViewStack > GtkBox.vertical > GtkBox.header.notebook.horizontal > GtkEventBox > GtkBox.horizontal > GtkBox 
> GtkBox > .button {