theme: Stylesheet papercuts and other visual fixes

- remove tiled preview corners; merge with misc.scss
- sync general label styles from libadwaita
- use variables in ibus css
- remove redundant spacing variable as its equal to padding
- use more global styles in screenshot css
- tidy up entry styles
- cleanup the networks dialog stylesheet
- make colours less dark
- cleanup the popover stylesheet
- cleanup the mixins for tiles and overview icons
- adjust the button style definitions on checked style
- add osd button definitions

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2172>

1 files changed, 0 insertions, 3 deletions

diff --git a/data/theme/gnome-shell-sass/widgets/_notifications.scss b/data/theme/gnome-shell-sass/widgets/_notifications.scss
index 194a5a4e5..7866767ea 100644
--- a/data/theme/gnome-shell-sass/widgets/_notifications.scss
+++ b/data/theme/gnome-shell-sass/widgets/_notifications.scss
@@ -4,9 +4,6 @@ $notification_banner_height: 64px;
 $notification_banner_width: 34em;
 $notification_banner_radius: $base_border_radius*1.5;
 
-// make radius of buttons fit in bubble corner (banner radius - width of focus ring)
-$notification_button_radius: ($notification_banner_radius - 2px);
-
 // Banner notifications
 .notification-banner {
   min-height: $notification_banner_height;