[libadwaita/wip/exalm/accent: 10/11] stylesheet: Add and use gtkmix()

[Alexander Mikhaylenko <alexm src gnome org>]

commit 87ad5cf8b0b88b761211f7aeebc437a061f29319
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Sat Jun 12 02:32:00 2021 +0500

    stylesheet: Add and use gtkmix()

 src/stylesheet/_colors.scss    | 4 ++--
 src/stylesheet/_functions.scss | 4 ++++
 2 files changed, 6 insertions(+), 2 deletions(-)
---
diff --git a/src/stylesheet/_colors.scss b/src/stylesheet/_colors.scss
index 7807957a..c801f491 100644
--- a/src/stylesheet/_colors.scss
+++ b/src/stylesheet/_colors.scss
@@ -43,8 +43,8 @@ $button_checked_active_color: gtkalpha(currentColor, .35);
 
 $fill_color: $accent_color;
 $fill_text_color: $accent_text;
-$fill_hover_color: #{"mix(#{$accent_color}, currentColor, .1)"};
-$fill_active_color: #{"mix(#{$accent_color}, black, .2)"};
+$fill_hover_color: gtkmix($accent_color, currentColor, 90%);
+$fill_active_color: gtkmix($accent_color, black, 80%);
 
 $slider_color: mix(white, $base_color, 80%);
 $slider_hover_color: white;
diff --git a/src/stylesheet/_functions.scss b/src/stylesheet/_functions.scss
index 7ceccd19..afc8b648 100644
--- a/src/stylesheet/_functions.scss
+++ b/src/stylesheet/_functions.scss
@@ -2,3 +2,7 @@
   @return unquote("alpha(#{$c},#{$a})");
 }
 
+@function gtkmix($c1,$c2,$r) {
+  $ratio: 1 -  $r / 100%; // match SCSS mix()
+  @return unquote("mix(#{$c1},#{$c2},#{$ratio})");
+}