Fix dark custom variant (#1441)

Co-authored-by: Julius Marminge <julius0216@outlook.com>

Author: carloschida

apps/nextjs/src/app/globals.css

@@ -4,7 +4,7 @@
 
 @source '../../../../packages/ui/src/*.{ts,tsx}';
 
-@custom-variant dark (&:is(.dark *));
+@custom-variant dark (&:where(.dark, .dark *));
 
 @utility container {
   margin-inline: auto;