[gnome-games/wip/exalm/devel-style] ui: Update devel style

[Alexander Mikhaylenko <alexm src gnome org>]

commit 02b53fb766c3f52d45e41f24ac4514676bc509b4
Author: Alexander Mikhaylenko <exalm7659 gmail com>
Date:   Sun Sep 16 12:48:50 2018 +0500

    ui: Update devel style
    
    Use the style from https://gitlab.gnome.org/GNOME/gtk/merge_requests/168

 data/gtk-style.css | 20 +++++++-------------
 1 file changed, 7 insertions(+), 13 deletions(-)
---
diff --git a/data/gtk-style.css b/data/gtk-style.css
index 83ae1888..09b97c55 100644
--- a/data/gtk-style.css
+++ b/data/gtk-style.css
@@ -14,19 +14,13 @@ gamesgamethumbnail {
 }
 
 .devel headerbar {
-       background: -gtk-icontheme("system-run-symbolic") right 0/350px 64px no-repeat,
-                   linear-gradient(to left, rgba (165, 177, 189, 0.5) 0,
-                                            rgba (165, 177, 189, 0.5) 200px,
-                                            rgba (  0,   0,   0,   0) 400px),
-                   @theme_bg_color;
-       border-color: @borders;
+  background: transparent -gtk-icontheme("system-run-symbolic") 80% 0/128px 128px no-repeat,
+              linear-gradient(to left,
+                              mix(@theme_selected_bg_color, @theme_bg_color, 0.5) 8%,
+                              @theme_bg_color 25%);
+  color: alpha(@theme_fg_color, 0.1);
 }
 
-.devel headerbar:backdrop {
-       background: -gtk-icontheme("system-run-symbolic") right 0/350px 64px no-repeat,
-                   linear-gradient(to left, rgba (165, 177, 189, 0.3) 0,
-                                            rgba (165, 177, 189, 0.3) 200px,
-                                            rgba (  0,   0,   0,   0) 400px),
-                   @theme_unfocused_bg_color;
-       border-color: @unfocused_borders;
+.devel headerbar label {
+  color: @theme_fg_color;
 }