Gtk-3.22&3.24&4.0: [WhiskerMenuApplet] Add some workarounds (2)

Enforce dimming ugly resize-grip in both top/bottom panel layouts.
diff --git a/gtk/sass/3.22/_3rd-party.scss b/gtk/sass/3.22/_3rd-party.scss
index 03ab6dd..e240816 100644
--- a/gtk/sass/3.22/_3rd-party.scss
+++ b/gtk/sass/3.22/_3rd-party.scss
@@ -2435,8 +2435,11 @@
   // why wasn't .popup class implemented in this window node? :/
   > decoration { box-shadow: $z-depth-3; }
 
-  stack > box > box.horizontal:first-child { // ugly resize-grip
-    widget { color: $outline_track_color; }
+  stack > box > box.horizontal {
+    &:first-child widget,
+    &:last-child > widget:last-child { // ugly resize-grip
+      color: $outline_track_color;
+    }
   }
 
   scrolledwindow {
diff --git a/gtk/sass/3.24/_3rd-party.scss b/gtk/sass/3.24/_3rd-party.scss
index a10caeb..01d9ed0 100644
--- a/gtk/sass/3.24/_3rd-party.scss
+++ b/gtk/sass/3.24/_3rd-party.scss
@@ -2435,8 +2435,11 @@
   // why wasn't .popup class implemented in this window node? :/
   > decoration { box-shadow: $z-depth-3; }
 
-  stack > box > box.horizontal:first-child { // ugly resize-grip
-    widget { color: $outline_track_color; }
+  stack > box > box.horizontal {
+    &:first-child widget,
+    &:last-child > widget:last-child { // ugly resize-grip
+      color: $outline_track_color;
+    }
   }
 
   scrolledwindow {
diff --git a/gtk/sass/4.0/_3rd-party.scss b/gtk/sass/4.0/_3rd-party.scss
index b33b617..7c1a7e5 100644
--- a/gtk/sass/4.0/_3rd-party.scss
+++ b/gtk/sass/4.0/_3rd-party.scss
@@ -2414,8 +2414,11 @@
   // why wasn't .popup class implemented in this window node? :/
   > decoration { box-shadow: $z-depth-3; }
 
-  stack > box > box.horizontal:first-child { // ugly resize-grip
-    widget { color: $outline_track_color; }
+  stack > box > box.horizontal {
+    &:first-child widget,
+    &:last-child > widget:last-child { // ugly resize-grip
+      color: $outline_track_color;
+    }
   }
 
   scrolledwindow {