[libadwaita/wip/exalm/card: 2/2] stylesheet: Add button.opaque style class

[Alexander Mikhaylenko <alexm src gnome org>]

commit f99e628bc25468b1c485f466854a7726035a7c2d
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Tue Oct 19 16:38:58 2021 +0500

    stylesheet: Add button.opaque style class
    
    Have an explicit way to do colored buttons instead of having apps abuse
    .suggested-action and .destructive-action.
    
    Fixes https://gitlab.gnome.org/GNOME/libadwaita/-/issues/251

 src/stylesheet/widgets/_buttons.scss | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)
---
diff --git a/src/stylesheet/widgets/_buttons.scss b/src/stylesheet/widgets/_buttons.scss
index dd6c06db..b5d6c643 100644
--- a/src/stylesheet/widgets/_buttons.scss
+++ b/src/stylesheet/widgets/_buttons.scss
@@ -145,7 +145,7 @@ button {
     }
   }
 
-  @at-root %filled_button {
+  @at-root %opaque_button {
     box-shadow: none;
 
     @include focus-ring($outer: true, $offset: 1px);
@@ -174,8 +174,15 @@ button {
     }
   }
 
+  &.opaque {
+    @extend %opaque_button;
+
+    background-color: gtkmix($bg_color, $fg_color, 85%);
+    color: $fg_color;
+  }
+
   &.destructive-action {
-    @extend %filled_button;
+    @extend %opaque_button;
 
     color: $destructive_fg_color;
 
@@ -185,7 +192,7 @@ button {
   }
 
   &.suggested-action {
-    @extend %filled_button;
+    @extend %opaque_button;
 
     color: $accent_fg_color;
 
@@ -468,7 +475,7 @@ splitbutton {
 
   &.suggested-action {
     > button, > menubutton > button {
-      @extend %filled_button;
+      @extend %opaque_button;
 
       color: $accent_fg_color;
 
@@ -480,7 +487,7 @@ splitbutton {
 
   &.destructive-action {
     > button, > menubutton > button {
-      @extend %filled_button;
+      @extend %opaque_button;
 
       color: $destructive_fg_color;