refactor(ui): enhance ambient glow effects with improved visibility and size adjustments

lib/main.dart

@@ -2,6 +2,7 @@ import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'core/router/app_router.dart';
 import 'core/theme/app_theme.dart';
+import 'core/theme/app_colors.dart';
 import 'core/providers/theme_provider.dart';
 
 void main() async {
@@ -24,6 +25,21 @@ class MyApp extends ConsumerWidget {
       darkTheme: AppTheme.darkTheme,
       themeMode: themeState.themeMode,
       routerConfig: router,
+      builder: (context, child) {
+        return Container(
+          decoration: BoxDecoration(
+            gradient: AppColors.grayGlossyGradient,
+            boxShadow: [
+              BoxShadow(
+                color: Colors.white.withOpacity(0.08),
+                blurRadius: 40,
+                spreadRadius: 20,
+              ),
+            ],
+          ),
+          child: child,
+        );
+      },
     );
   }
 }