[gtk/wip/jimmac/osd-spinbutton] Adwaita: osd spinbutton specificity bump

[Jakub Steiner <jimmac src gnome org>]

commit 78236bfdbeded9af6d5de5e04b47cbba121f8575
Author: Jakub Steiner <jimmac gmail com>
Date:   Wed Sep 23 10:16:55 2020 +0200

    Adwaita: osd spinbutton specificity bump
    
    - mimic the peculiar selector from the normal style onto osd to
      override.
    
    Fixes https://gitlab.gnome.org/GNOME/gtk/-/issues/2769

 gtk/theme/Adwaita/_common.scss | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/gtk/theme/Adwaita/_common.scss b/gtk/theme/Adwaita/_common.scss
index 7ffc6f2f2f..2ab2e5e5f2 100644
--- a/gtk/theme/Adwaita/_common.scss
+++ b/gtk/theme/Adwaita/_common.scss
@@ -1078,7 +1078,8 @@ spinbutton {
       @extend %spinbutton_horz_entry;
     }
 
-    > button {
+    > button.image-button.up:not(.flat),
+    > button.image-button.down:not(.flat) {
       @include button(undecorated);
 
       color: $osd_fg_color;