[libadwaita/wip/exalm/buttons-5: 19/20] stylesheet: Lighten header bar

[Alexander Mikhaylenko <alexm src gnome org>]

commit 6505b1f837c9d1c69733e24b0d46eec06b4de5bb
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Thu Jun 10 01:57:00 2021 +0500

    stylesheet: Lighten header bar
    
    Remove the checked buttons override.
    
    Lighten up AdwTabBar to match it.
    
    Fixes https://gitlab.gnome.org/GNOME/libadwaita/-/issues/149

 src/stylesheet/_colors.scss             |  2 +-
 src/stylesheet/widgets/_header-bar.scss | 37 +++++++++------------------------
 src/stylesheet/widgets/_tab-view.scss   |  2 +-
 3 files changed, 12 insertions(+), 29 deletions(-)
---
diff --git a/src/stylesheet/_colors.scss b/src/stylesheet/_colors.scss
index dab29663..a9840a26 100644
--- a/src/stylesheet/_colors.scss
+++ b/src/stylesheet/_colors.scss
@@ -15,7 +15,7 @@ $borders_edge: if($variant == 'light', transparentize(white, 0.2), transparentiz
 $link_color: if($variant == 'light', darken($selected_bg_color, 10%), lighten($selected_bg_color, 20%));
 $link_visited_color: if($variant == 'light', darken($selected_bg_color, 20%), lighten($selected_bg_color, 
10%));
 $dark_fill: mix($borders_color, $bg_color, 50%);
-$headerbar_bg_color: if($variant == 'light', lighten($bg_color, 5%), darken($bg_color, 3%));
+$headerbar_bg_color: $bg_color;
 $menu_color: $base_color;
 
 $view_hover_color: #{"alpha(currentColor, .07)"};
diff --git a/src/stylesheet/widgets/_header-bar.scss b/src/stylesheet/widgets/_header-bar.scss
index 9a834c6f..cb1c0458 100644
--- a/src/stylesheet/widgets/_header-bar.scss
+++ b/src/stylesheet/widgets/_header-bar.scss
@@ -1,17 +1,10 @@
-$_header_bar_color: darken($bg_color, 10%);
-$_header_bar_gradient: linear-gradient(to top, darken($_header_bar_color, 2%), lighten($_header_bar_color, 
1%));
-
-@if $variant == 'dark' {
-  $_header_bar_gradient: linear-gradient(to top, lighten($_header_bar_color, 4%), 
lighten($_header_bar_color, 6%));
-}
-
 headerbar {
   padding: 0 6px;
   min-height: 46px;
   border-width: 0 0 1px;
   border-style: solid;
   border-color: $alt_borders_color;
-  background-image: $_header_bar_gradient;
+  background-color: $headerbar_bg_color;
 
   > windowhandle > box {
     &,
@@ -22,7 +15,7 @@ headerbar {
   }
 
   &:backdrop {
-    background-image: linear-gradient(to top, $bg_color, $bg_color);
+    background-color: $headerbar_bg_color;
 
     transition: $backdrop_transition;
 
@@ -34,15 +27,6 @@ headerbar {
     }
   }
 
-  /* Darken switchbuttons for headerbars. issue #1588 */
-  stackswitcher > button:checked,
-  button:not(.flat).toggle:checked {
-
-    background: if($variant == 'light', image(darken($bg_color, 17%)), image(darken($bg_color, 9%)));
-    border-color: darken($borders_color, 3%);
-    border-top-color: darken($borders_color, 8%);
-  }
-
   &.default-decoration {
     min-height: 28px;
     padding: 4px;
@@ -143,22 +127,21 @@ windowtitle {
 
 window.devel {
   headerbar {
-    $c: darken($bg_color, 10%);
     $gradient: cross-fade(10% -gtk-icontheme("system-run-symbolic"), image(transparent)) 90% 0/256px 256px 
no-repeat,
-               linear-gradient(to right, transparent 65%, transparentize($selected_bg_color, 0.8)),
-               $_header_bar_gradient;
+               linear-gradient(to right, transparent 65%, transparentize($selected_bg_color, 0.8));
+
     @if $variant == 'dark' {
       $gradient: cross-fade(10% -gtk-icontheme("system-run-symbolic"), image(transparent)) 90% 0/256px 256px 
no-repeat,
-                 linear-gradient(to right, transparent 65%, transparentize($selected_bg_color, 0.9)),
-                 $_header_bar_gradient;
+                 linear-gradient(to right, transparent 65%, transparentize($selected_bg_color, 0.9));
     }
 
-    background: $bg_color $gradient;
+    background: $headerbar_bg_color $gradient;
 
     &:backdrop {
-      background: $bg_color cross-fade(5% -gtk-icontheme("system-run-symbolic"), image(transparent)) 90% 
0/256px 256px no-repeat,
-                  linear-gradient(to right, transparent 65%, transparent),
-                  linear-gradient(to top, $bg_color, $bg_color);
+      $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 $gradient;
     }
   }
 }
diff --git a/src/stylesheet/widgets/_tab-view.scss b/src/stylesheet/widgets/_tab-view.scss
index de13d2f6..39bdd216 100644
--- a/src/stylesheet/widgets/_tab-view.scss
+++ b/src/stylesheet/widgets/_tab-view.scss
@@ -1,4 +1,4 @@
-$tab_bg: darken($bg_color, if($variant == 'dark', 6%, 12%));
+$tab_bg: darken($headerbar_bg_color, 6%);
 
 @mixin undershoot-gradient($dir) {
   @if $variant == 'dark' {