chore: update dependencies and configuration for Tailwind CSS

- Added "@tailwindcss/postcss" to package.json dependencies.
- Updated "tailwindcss" version to "^4.3.0" in package.json.
- Modified postcss.config.mjs to use "@tailwindcss/postcss" instead of "tailwindcss".
- Changed darkMode configuration in tailwind.config.ts to a string format.

package.json

@@ -22,6 +22,7 @@
     "@radix-ui/react-slot": "^1.2.4",
     "@radix-ui/react-toast": "^1.2.15",
     "@supabase/ssr": "^0.10.2",
+    "@tailwindcss/postcss": "^4.3.0",
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",
     "dexie": "^4.4.2",
@@ -30,6 +31,7 @@
     "lucide-react": "^1.14.0",
     "next": "^16.2.6",
     "next-themes": "^0.4.6",
+    "poyraz-ui": "^2.0.1",
     "radix-ui": "^1.4.3",
     "react": "^19.0.0",
     "react-dom": "^19.0.0",
@@ -51,7 +53,7 @@
     "eslint": "^9.18.0",
     "eslint-config-next": "^16.2.6",
     "postcss": "^8.5.1",
-    "tailwindcss": "^3.4.17",
+    "tailwindcss": "^4.3.0",
     "typescript": "^5.7.3"
   }
 }