[gtk/wip/jimmac/notebook-legibility] Adwaita: notebook legibility fixes

[Jakub Steiner <jimmac src gnome org>]

commit ec54399d8999635167a8720184431d99bb2136a5
Author: Jakub Steiner <jimmac gmail com>
Date:   Tue Jun 23 19:54:54 2020 +0200

    Adwaita: notebook legibility fixes
    
    - make inactive tabs more legible
    
    Fixes https://gitlab.gnome.org/GNOME/gtk/-/issues/2652

 gtk/theme/Adwaita/_common.scss | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)
---
diff --git a/gtk/theme/Adwaita/_common.scss b/gtk/theme/Adwaita/_common.scss
index d94962dd98..77152908ef 100644
--- a/gtk/theme/Adwaita/_common.scss
+++ b/gtk/theme/Adwaita/_common.scss
@@ -1818,10 +1818,10 @@ notebook {
       > tabs {
         margin-bottom: -2px;
         > tab {
-          &:hover { box-shadow: inset 0 -3px $borders_color; }
+          &:hover { box-shadow: inset 0 -4px $borders_color; }
 
 
-          &:checked { box-shadow: inset 0 -3px $selected_bg_color; }
+          &:checked { box-shadow: inset 0 -4px $selected_bg_color; }
         }
       }
     }
@@ -1831,9 +1831,9 @@ notebook {
       > tabs {
         margin-top: -2px;
         > tab {
-          &:hover { box-shadow: inset 0 3px $borders_color; }
+          &:hover { box-shadow: inset 0 4px $borders_color; }
 
-          &:checked { box-shadow: inset 0 3px $selected_bg_color; }
+          &:checked { box-shadow: inset 0 4px $selected_bg_color; }
         }
       }
     }
@@ -1843,9 +1843,9 @@ notebook {
       > tabs {
         margin-right: -2px;
         > tab {
-          &:hover { box-shadow: inset -3px 0 $borders_color; }
+          &:hover { box-shadow: inset -4px 0 $borders_color; }
 
-          &:checked { box-shadow: inset -3px 0 $selected_bg_color; }
+          &:checked { box-shadow: inset -4px 0 $selected_bg_color; }
         }
       }
     }
@@ -1855,9 +1855,9 @@ notebook {
       > tabs {
         margin-left: -2px;
         > tab {
-          &:hover { box-shadow: inset 3px 0 $borders_color; }
+          &:hover { box-shadow: inset 4px 0 $borders_color; }
 
-          &:checked { box-shadow: inset 3px 0 $selected_bg_color; }
+          &:checked { box-shadow: inset 4px 0 $selected_bg_color; }
         }
       }
     }
@@ -1934,14 +1934,15 @@ notebook {
       min-width: 30px;
       padding: 3px 12px;
 
-      color: $insensitive_fg_color;
-      font-weight: bold;
+      color: $fg_color;
+      font-weight: normal;
 
       border-width: 1px;         // for reorderable tabs
       border-color: transparent; //
 
       &:hover {
-        color: mix($insensitive_fg_color, $fg_color, 50%);
+        color: $fg_color;
+        background-color: darken($bg_color,4%);
 
         &.reorderable-page {
           border-color: transparentize($borders_color, 0.7);