[libadwaita/wip/exalm/headerbars: 9/12] stylesheet: Move the devel headerbar style to a nested widget

[Alexander Mikhaylenko <alexm src gnome org>]

commit 1bae0d4097bbc3a9ba5cfc518eaf6056540f131c
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Wed Jun 16 16:54:03 2021 +0500

    stylesheet: Move the devel headerbar style to a nested widget
    
    This way we get automatic backdrop state and less chance of collision with
    app developers changing header bar colors.

 src/stylesheet/widgets/_header-bar.scss | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)
---
diff --git a/src/stylesheet/widgets/_header-bar.scss b/src/stylesheet/widgets/_header-bar.scss
index 224c9b03..78b4435a 100644
--- a/src/stylesheet/widgets/_header-bar.scss
+++ b/src/stylesheet/widgets/_header-bar.scss
@@ -130,7 +130,7 @@ windowtitle {
 // Development versions of apps to use a differently styled headerbar
 
 window.devel {
-  headerbar {
+  headerbar > windowhandle {
     $gradient: cross-fade(10% -gtk-icontheme("system-run-symbolic"), image(transparent)) 90% 0/256px 256px 
no-repeat,
                linear-gradient(to right, transparent 65%, gtkalpha($accent_color, 0.2));
 
@@ -139,13 +139,6 @@ window.devel {
                  linear-gradient(to right, transparent 65%, gtkalpha($accent_color, 0.1));
     }
 
-    background: $headerbar_bg_color $gradient;
-
-    &:backdrop {
-      $gradient: cross-fade(5% -gtk-icontheme("system-run-symbolic"), image(transparent)) 90% 0/256px 256px 
no-repeat,
-                 linear-gradient(to right, transparent 65%, transparent);
-
-      background: $headerbar_bg_color $gradient;
-    }
+    background: $gradient;
   }
 }