uf 액션 토스트 공통화 및 SnackBar 제거

userfront/lib/core/ui/toast_service.dart

@@ -0,0 +1,234 @@
+import 'dart:async';
+import 'dart:math' as math;
+
+import 'package:flutter/material.dart';
+
+enum ToastType { success, error, info }
+
+class _ToastItem {
+  const _ToastItem({
+    required this.id,
+    required this.message,
+    required this.type,
+  });
+
+  final String id;
+  final String message;
+  final ToastType type;
+}
+
+class ToastService {
+  static const Duration _displayDuration = Duration(milliseconds: 3000);
+  static final ValueNotifier<List<_ToastItem>> _toasts =
+      ValueNotifier<List<_ToastItem>>(<_ToastItem>[]);
+
+  static void success(String message) {
+    show(message, type: ToastType.success);
+  }
+
+  static void error(String message) {
+    show(message, type: ToastType.error);
+  }
+
+  static void info(String message) {
+    show(message, type: ToastType.info);
+  }
+
+  static void show(String message, {ToastType type = ToastType.success}) {
+    final trimmed = message.trim();
+    if (trimmed.isEmpty) {
+      return;
+    }
+
+    final item = _ToastItem(
+      id: '${DateTime.now().microsecondsSinceEpoch}-${_toasts.value.length}',
+      message: trimmed,
+      type: type,
+    );
+
+    _toasts.value = [..._toasts.value, item];
+
+    unawaited(
+      Future<void>.delayed(_displayDuration, () {
+        _remove(item.id);
+      }),
+    );
+  }
+
+  static void _remove(String id) {
+    final next = _toasts.value.where((toast) => toast.id != id).toList();
+    if (next.length == _toasts.value.length) {
+      return;
+    }
+    _toasts.value = next;
+  }
+}
+
+class ToastViewport extends StatelessWidget {
+  const ToastViewport({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return IgnorePointer(
+      ignoring: true,
+      child: SafeArea(
+        child: ValueListenableBuilder<List<_ToastItem>>(
+          valueListenable: ToastService._toasts,
+          builder: (context, toasts, _) {
+            if (toasts.isEmpty) {
+              return const SizedBox.shrink();
+            }
+
+            final media = MediaQuery.of(context);
+            final width = math.min(320.0, media.size.width - 32);
+
+            return Align(
+              alignment: Alignment.bottomRight,
+              child: Padding(
+                padding: const EdgeInsets.only(right: 16, bottom: 16),
+                child: SizedBox(
+                  width: width > 0 ? width : 320,
+                  child: Column(
+                    mainAxisSize: MainAxisSize.min,
+                    crossAxisAlignment: CrossAxisAlignment.end,
+                    children: [
+                      for (final toast in toasts)
+                        Padding(
+                          padding: const EdgeInsets.only(top: 8),
+                          child: _ToastCard(item: toast),
+                        ),
+                    ],
+                  ),
+                ),
+              ),
+            );
+          },
+        ),
+      ),
+    );
+  }
+}
+
+class _ToastCard extends StatefulWidget {
+  const _ToastCard({required this.item});
+
+  final _ToastItem item;
+
+  @override
+  State<_ToastCard> createState() => _ToastCardState();
+}
+
+class _ToastCardState extends State<_ToastCard> {
+  bool _visible = false;
+
+  @override
+  void initState() {
+    super.initState();
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      if (!mounted) {
+        return;
+      }
+      setState(() {
+        _visible = true;
+      });
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final scheme = _toastColorScheme(widget.item.type);
+    final icon = _toastIcon(widget.item.type);
+
+    return AnimatedSlide(
+      duration: const Duration(milliseconds: 300),
+      curve: Curves.easeOutCubic,
+      offset: _visible ? Offset.zero : const Offset(1, 0),
+      child: AnimatedOpacity(
+        duration: const Duration(milliseconds: 220),
+        opacity: _visible ? 1 : 0,
+        child: DecoratedBox(
+          decoration: BoxDecoration(
+            color: scheme.background,
+            borderRadius: BorderRadius.circular(8),
+            border: Border.all(color: scheme.border),
+            boxShadow: const [
+              BoxShadow(
+                color: Color(0x26000000),
+                blurRadius: 16,
+                offset: Offset(0, 6),
+              ),
+            ],
+          ),
+          child: Padding(
+            padding: const EdgeInsets.all(16),
+            child: Row(
+              crossAxisAlignment: CrossAxisAlignment.center,
+              children: [
+                Icon(icon, size: 20, color: scheme.foreground),
+                const SizedBox(width: 12),
+                Expanded(
+                  child: Text(
+                    widget.item.message,
+                    style: TextStyle(
+                      color: scheme.foreground,
+                      fontSize: 14,
+                      fontWeight: FontWeight.w400,
+                      height: 1.2,
+                      decoration: TextDecoration.none,
+                    ),
+                  ),
+                ),
+              ],
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+
+  _ToastColorScheme _toastColorScheme(ToastType type) {
+    switch (type) {
+      case ToastType.success:
+        return const _ToastColorScheme(
+          background: Color(0xFFECFDF5),
+          border: Color(0xFFA7F3D0),
+          foreground: Color(0xFF065F46),
+        );
+      case ToastType.error:
+        return const _ToastColorScheme(
+          background: Color(0xFFFFF1F2),
+          border: Color(0xFFFDA4AF),
+          foreground: Color(0xFF9F1239),
+        );
+      case ToastType.info:
+        return const _ToastColorScheme(
+          background: Color(0xFFEFF6FF),
+          border: Color(0xFFBFDBFE),
+          foreground: Color(0xFF1E40AF),
+        );
+    }
+  }
+
+  IconData _toastIcon(ToastType type) {
+    switch (type) {
+      case ToastType.success:
+        return Icons.check_circle_outline;
+      case ToastType.error:
+        return Icons.error_outline;
+      case ToastType.info:
+        return Icons.info_outline;
+    }
+  }
+}
+
+class _ToastColorScheme {
+  const _ToastColorScheme({
+    required this.background,
+    required this.border,
+    required this.foreground,
+  });
+
+  final Color background;
+  final Color border;
+  final Color foreground;
+}

userfront/lib/features/admin/presentation/create_user_screen.dart

@@ -2,6 +2,7 @@ import 'package:flutter/material.dart';
 import 'package:go_router/go_router.dart';
 import '../../../../core/services/auth_proxy_service.dart';
 import '../../../../core/i18n/locale_utils.dart';
+import '../../../../core/ui/toast_service.dart';
 
 class CreateUserScreen extends StatefulWidget {
   const CreateUserScreen({super.key});
@@ -86,12 +87,7 @@ class _CreateUserScreenState extends State<CreateUserScreen> {
       }
     } else {
       if (mounted) {
-        ScaffoldMessenger.of(context).showSnackBar(
+        ToastService.error('Invalid Password. Access Denied.');
-          const SnackBar(
-            content: Text('Invalid Password. Access Denied.'),
-            backgroundColor: Colors.red,
-          ),
-        );
         context.go(buildLocalizedHomePath(Uri.base)); // Kick out
       }
     }
@@ -144,12 +140,7 @@ class _CreateUserScreenState extends State<CreateUserScreen> {
       );
 
       if (mounted) {
-        ScaffoldMessenger.of(context).showSnackBar(
+        ToastService.success('User created successfully!');
-          const SnackBar(
-            content: Text('User created successfully!'),
-            backgroundColor: Colors.green,
-          ),
-        );
         _formKey.currentState!.reset();
         _loginIdController.clear();
         _emailController.clear();
@@ -158,9 +149,7 @@ class _CreateUserScreenState extends State<CreateUserScreen> {
       }
     } catch (e) {
       if (mounted) {
-        ScaffoldMessenger.of(context).showSnackBar(
+        ToastService.error('Error: $e');
-          SnackBar(content: Text('Error: $e'), backgroundColor: Colors.red),
-        );
       }
     } finally {
       if (mounted) setState(() => _isLoading = false);

userfront/lib/features/admin/presentation/user_management_screen.dart

@@ -3,6 +3,7 @@ import 'package:go_router/go_router.dart';
 import 'dart:async';
 import '../../../../core/services/auth_proxy_service.dart';
 import '../../../../core/i18n/locale_utils.dart';
+import '../../../../core/ui/toast_service.dart';
 
 class UserManagementScreen extends StatefulWidget {
   const UserManagementScreen({super.key});
@@ -108,12 +109,7 @@ class _UserManagementScreenState extends State<UserManagementScreen>
       }
     } else {
       if (mounted) {
-        ScaffoldMessenger.of(context).showSnackBar(
+        ToastService.error('Invalid Password');
-          const SnackBar(
-            content: Text('Invalid Password'),
-            backgroundColor: Colors.red,
-          ),
-        );
         context.go(buildLocalizedHomePath(Uri.base));
       }
     }
@@ -343,16 +339,12 @@ class _UserManagementScreenState extends State<UserManagementScreen>
   // --- UI Helpers ---
   void _showError(String msg) {
     if (!mounted) return;
-    ScaffoldMessenger.of(
+    ToastService.error(msg);
-      context,
-    ).showSnackBar(SnackBar(content: Text(msg), backgroundColor: Colors.red));
   }
 
   void _showSuccess(String msg) {
     if (!mounted) return;
-    ScaffoldMessenger.of(
+    ToastService.success(msg);
-      context,
-    ).showSnackBar(SnackBar(content: Text(msg), backgroundColor: Colors.green));
   }
 
   @override

userfront/lib/features/auth/presentation/consent_screen.dart

@@ -4,6 +4,7 @@ import 'package:userfront/i18n.dart';
 import 'package:userfront/core/i18n/locale_utils.dart';
 import 'package:userfront/core/services/auth_proxy_service.dart';
 import 'package:userfront/core/services/web_window.dart';
+import 'package:userfront/core/ui/toast_service.dart';
 
 class ConsentScreen extends StatefulWidget {
   final String consentChallenge;
@@ -187,16 +188,11 @@ class _ConsentScreenState extends State<ConsentScreen> {
       } catch (e) {
         setState(() => _isSubmitting = false);
         if (mounted) {
-          ScaffoldMessenger.of(context).showSnackBar(
+          ToastService.error(
-            SnackBar(
+            tr(
-              content: Text(
+              'msg.userfront.consent.cancel.error',
-                tr(
+              fallback: 'An error occurred while cancelling consent: {{error}}',
-                  'msg.userfront.consent.cancel.error',
+              params: {'error': '$e'},
-                  fallback:
-                      'An error occurred while cancelling consent: {{error}}',
-                  params: {'error': '$e'},
-                ),
-              ),
             ),
           );
         }
@@ -419,7 +415,7 @@ class _ConsentScreenState extends State<ConsentScreen> {
                         )
                       : Text(
                           tr('ui.userfront.consent.accept'),
-                          style: TextStyle(
+                          style: const TextStyle(
                             fontSize: 16,
                             fontWeight: FontWeight.bold,
                           ),

userfront/lib/features/auth/presentation/forgot_password_screen.dart

@@ -1,5 +1,6 @@
 import 'package:flutter/material.dart';
 import '../../../core/services/auth_proxy_service.dart';
+import '../../../core/ui/toast_service.dart';
 import 'package:userfront/i18n.dart';
 
 class ForgotPasswordScreen extends StatefulWidget {
@@ -46,12 +47,7 @@ class _ForgotPasswordScreenState extends State<ForgotPasswordScreen> {
         drySend: _drySendEnabled,
       );
       if (mounted) {
-        ScaffoldMessenger.of(context).showSnackBar(
+        ToastService.success(tr('msg.userfront.forgot.sent'));
-          SnackBar(
-            content: Text(tr('msg.userfront.forgot.sent')),
-            backgroundColor: Colors.green,
-          ),
-        );
         Navigator.of(context).pop();
       }
     } catch (e) {
@@ -68,9 +64,7 @@ class _ForgotPasswordScreenState extends State<ForgotPasswordScreen> {
   }
 
   void _showError(String message) {
-    ScaffoldMessenger.of(context).showSnackBar(
+    ToastService.error(message);
-      SnackBar(content: Text(message), backgroundColor: Colors.red),
-    );
   }
 
   bool _parseBoolParam(String? value) {

userfront/lib/features/auth/presentation/login_screen.dart

@@ -18,6 +18,7 @@ import '../domain/cookie_session_policy.dart';
 import '../domain/login_link_route_policy.dart';
 import '../../profile/domain/notifiers/profile_notifier.dart';
 import '../../../core/services/web_window.dart';
+import '../../../core/ui/toast_service.dart';
 
 class LoginScreen extends ConsumerStatefulWidget {
   final String? verificationToken;
@@ -1153,9 +1154,7 @@ class _LoginScreenState extends ConsumerState<LoginScreen>
 
   void _showError(String message) {
     if (!mounted) return;
-    ScaffoldMessenger.of(context).showSnackBar(
+    ToastService.error(message);
-      SnackBar(content: Text(message), backgroundColor: Colors.red),
-    );
     try {
       AuthProxyService.logError(message);
     } catch (e) {
@@ -1165,9 +1164,7 @@ class _LoginScreenState extends ConsumerState<LoginScreen>
 
   void _showInfo(String message) {
     if (!mounted) return;
-    ScaffoldMessenger.of(context).showSnackBar(
+    ToastService.success(message);
-      SnackBar(content: Text(message), backgroundColor: Colors.green),
-    );
   }
 
   void _logTokenDetails(String jwt) {

userfront/lib/features/auth/presentation/qr_scan_screen_stub.dart

@@ -1,6 +1,7 @@
 import 'package:flutter/material.dart';
 import 'package:go_router/go_router.dart';
 import 'package:userfront/i18n.dart';
+import 'package:userfront/core/ui/toast_service.dart';
 
 import 'qr_scan_route.dart';
 
@@ -23,15 +24,8 @@ class _QRScanScreenState extends State<QRScanScreen> {
   void _submit() {
     final raw = _controller.text.trim();
     if (raw.isEmpty) {
-      ScaffoldMessenger.of(context).showSnackBar(
+      ToastService.info(
-        SnackBar(
+        tr('msg.userfront.qr.permission_required', fallback: '카메라 권한이 필요합니다.'),
-          content: Text(
-            tr(
-              'msg.userfront.qr.permission_required',
-              fallback: '카메라 권한이 필요합니다.',
-            ),
-          ),
-        ),
       );
       return;
     }

userfront/lib/features/auth/presentation/reset_password_screen.dart

@@ -2,6 +2,7 @@ import 'package:flutter/material.dart';
 import 'package:go_router/go_router.dart';
 import '../../../core/i18n/locale_utils.dart';
 import '../../../core/services/auth_proxy_service.dart';
+import '../../../core/ui/toast_service.dart';
 import 'package:userfront/i18n.dart';
 
 class ResetPasswordScreen extends StatefulWidget {
@@ -84,12 +85,7 @@ class _ResetPasswordScreenState extends State<ResetPasswordScreen> {
       );
 
       if (mounted) {
-        ScaffoldMessenger.of(context).showSnackBar(
+        ToastService.success(tr('msg.userfront.reset.success'));
-          SnackBar(
-            content: Text(tr('msg.userfront.reset.success')),
-            backgroundColor: Colors.green,
-          ),
-        );
         context.go(buildLocalizedSigninPath(Uri.base));
       }
     } catch (e) {
@@ -109,9 +105,7 @@ class _ResetPasswordScreenState extends State<ResetPasswordScreen> {
   }
 
   void _showError(String message) {
-    ScaffoldMessenger.of(context).showSnackBar(
+    ToastService.error(message);
-      SnackBar(content: Text(message), backgroundColor: Colors.red),
-    );
   }
 
   String _buildPolicyDescription() {

userfront/lib/features/dashboard/presentation/dashboard_screen.dart

@@ -15,6 +15,7 @@ import '../../../../core/services/http_client.dart';
 import '../../../../core/i18n/locale_utils.dart';
 import '../../../../core/widgets/language_selector.dart';
 import '../../../../core/ui/layout_breakpoints.dart';
+import '../../../../core/ui/toast_service.dart';
 import '../../profile/domain/notifiers/profile_notifier.dart';
 import '../domain/dashboard_providers.dart';
 import '../domain/models.dart' hide LinkedRp;
@@ -104,14 +105,10 @@ class _DashboardScreenState extends ConsumerState<DashboardScreen> {
     try {
       await ref.read(linkedRpsProvider.notifier).revokeRp(clientId);
       if (mounted) {
-        ScaffoldMessenger.of(context).showSnackBar(
+        ToastService.success(
-          SnackBar(
+          tr(
-            content: Text(
+            'msg.userfront.dashboard.revoke.success',
-              tr(
+            params: {'app': appName},
-                'msg.userfront.dashboard.revoke.success',
-                params: {'app': appName},
-              ),
-            ),
           ),
         );
         setState(() {
@@ -121,15 +118,8 @@ class _DashboardScreenState extends ConsumerState<DashboardScreen> {
       }
     } catch (e) {
       if (mounted) {
-        ScaffoldMessenger.of(context).showSnackBar(
+        ToastService.error(
-          SnackBar(
+          tr('msg.userfront.dashboard.revoke.error', params: {'error': '$e'}),
-            content: Text(
-              tr(
-                'msg.userfront.dashboard.revoke.error',
-                params: {'error': '$e'},
-              ),
-            ),
-          ),
         );
       }
     } finally {
@@ -547,12 +537,8 @@ class _DashboardScreenState extends ConsumerState<DashboardScreen> {
           : () async {
               await Clipboard.setData(ClipboardData(text: approvedSessionId));
               if (mounted) {
-                ScaffoldMessenger.of(context).showSnackBar(
+                ToastService.info(
-                  SnackBar(
+                  tr('msg.userfront.dashboard.session_id_copied'),
-                    content: Text(
-                      tr('msg.userfront.dashboard.session_id_copied'),
-                    ),
-                  ),
                 );
               }
             },
@@ -626,12 +612,8 @@ class _DashboardScreenState extends ConsumerState<DashboardScreen> {
           : () async {
               await Clipboard.setData(ClipboardData(text: approvedSessionId));
               if (mounted) {
-                ScaffoldMessenger.of(context).showSnackBar(
+                ToastService.info(
-                  SnackBar(
+                  tr('msg.userfront.dashboard.session_id_copied'),
-                    content: Text(
-                      tr('msg.userfront.dashboard.session_id_copied'),
-                    ),
-                  ),
                 );
               }
             },
@@ -1280,7 +1262,6 @@ class _DashboardScreenState extends ConsumerState<DashboardScreen> {
         cursor: SystemMouseCursors.click,
         child: GestureDetector(
           onTap: () async {
-            final messenger = ScaffoldMessenger.of(context);
             final itemUrl = item.url;
             if (itemUrl != null && itemUrl.isNotEmpty) {
               final uri = Uri.parse(itemUrl);
@@ -1290,18 +1271,10 @@ class _DashboardScreenState extends ConsumerState<DashboardScreen> {
                 await launchUrl(uri);
                 return;
               }
-              messenger.showSnackBar(
+              ToastService.error(tr('msg.userfront.dashboard.link_open_error'));
-                SnackBar(
-                  content: Text(tr('msg.userfront.dashboard.link_open_error')),
-                ),
-              );
             } else {
               if (!mounted) return;
-              messenger.showSnackBar(
+              ToastService.info(tr('msg.userfront.dashboard.link_missing'));
-                SnackBar(
-                  content: Text(tr('msg.userfront.dashboard.link_missing')),
-                ),
-              );
             }
           },
           child: opaqueCard,

userfront/lib/features/profile/presentation/pages/profile_page.dart

@@ -7,6 +7,7 @@ import '../../../../core/notifiers/auth_notifier.dart';
 import '../../../../core/i18n/locale_utils.dart';
 import '../../../../core/services/auth_token_store.dart';
 import '../../../../core/ui/layout_breakpoints.dart';
+import '../../../../core/ui/toast_service.dart';
 import '../../../../core/widgets/language_selector.dart';
 import '../../data/models/user_profile_model.dart';
 import '../../domain/notifiers/profile_notifier.dart';
@@ -202,21 +203,15 @@ class _ProfilePageState extends ConsumerState<ProfilePage> {
         _isVerifying = false;
       });
       if (mounted) {
-        ScaffoldMessenger.of(context).showSnackBar(
+        ToastService.info(tr('msg.userfront.profile.phone.code_sent'));
-          SnackBar(content: Text(tr('msg.userfront.profile.phone.code_sent'))),
-        );
       }
     } catch (e) {
       setState(() => _isVerifying = false);
       if (mounted) {
-        ScaffoldMessenger.of(context).showSnackBar(
+        ToastService.error(
-          SnackBar(
+          tr(
-            content: Text(
+            'msg.userfront.profile.phone.send_failed',
-              tr(
+            params: {'error': e.toString()},
-                'msg.userfront.profile.phone.send_failed',
-                params: {'error': e.toString()},
-              ),
-            ),
           ),
         );
       }
@@ -236,21 +231,15 @@ class _ProfilePageState extends ConsumerState<ProfilePage> {
         _isVerifying = false;
       });
       if (mounted) {
-        ScaffoldMessenger.of(context).showSnackBar(
+        ToastService.success(tr('msg.userfront.profile.phone.verified'));
-          SnackBar(content: Text(tr('msg.userfront.profile.phone.verified'))),
-        );
       }
     } catch (e) {
       setState(() => _isVerifying = false);
       if (mounted) {
-        ScaffoldMessenger.of(context).showSnackBar(
+        ToastService.error(
-          SnackBar(
+          tr(
-            content: Text(
+            'msg.userfront.profile.phone.verify_failed',
-              tr(
+            params: {'error': e.toString()},
-                'msg.userfront.profile.phone.verify_failed',
-                params: {'error': e.toString()},
-              ),
-            ),
           ),
         );
       }
@@ -302,8 +291,9 @@ class _ProfilePageState extends ConsumerState<ProfilePage> {
       _newPasswordController?.clear();
       _confirmPasswordController?.clear();
       setState(() {
-        _passwordSuccess = tr('msg.userfront.profile.password.changed');
+        _passwordSuccess = null;
       });
+      ToastService.success(tr('msg.userfront.profile.password.changed'));
     } catch (e) {
       final message = e.toString().replaceFirst('Exception: ', '');
       setState(() {
@@ -312,6 +302,12 @@ class _ProfilePageState extends ConsumerState<ProfilePage> {
           params: {'error': message},
         );
       });
+      ToastService.error(
+        tr(
+          'msg.userfront.profile.password.change_failed',
+          params: {'error': message},
+        ),
+      );
     } finally {
       if (mounted) {
         setState(() => _isPasswordSaving = false);
@@ -338,7 +334,7 @@ class _ProfilePageState extends ConsumerState<ProfilePage> {
       _debugLog('save_skip', reason: 'saving_in_flight');
       return;
     }
-    
+
     setState(() {
       _fieldSaveError = null;
     });
@@ -411,7 +407,7 @@ class _ProfilePageState extends ConsumerState<ProfilePage> {
     setState(() {
       _isSavingField = true;
     });
-    
+
     _debugLog('save_dispatch', field: currentField, changed: true);
 
     try {
@@ -431,9 +427,7 @@ class _ProfilePageState extends ConsumerState<ProfilePage> {
           _editingField = null;
         });
         _debugLog('save_success', field: currentField);
-        ScaffoldMessenger.of(context).showSnackBar(
+        ToastService.success(tr('msg.userfront.profile.update_success'));
-          SnackBar(content: Text(tr('msg.userfront.profile.update_success'))),
-        );
       }
     } catch (e) {
       _debugLog('save_failed', field: currentField, reason: e.toString());
@@ -711,7 +705,9 @@ class _ProfilePageState extends ConsumerState<ProfilePage> {
             const SizedBox(width: 8),
             OutlinedButton(
               key: Key('profile-$field-cancel-button'),
-              onPressed: isUpdating || _isSavingField ? null : () => _cancelEditing(profile),
+              onPressed: isUpdating || _isSavingField
+                  ? null
+                  : () => _cancelEditing(profile),
               child: Text(tr('ui.common.cancel')),
             ),
           ],
@@ -798,7 +794,9 @@ class _ProfilePageState extends ConsumerState<ProfilePage> {
             ),
             const SizedBox(width: 8),
             OutlinedButton(
-              onPressed: isUpdating || _isSavingField ? null : () => _cancelEditing(profile),
+              onPressed: isUpdating || _isSavingField
+                  ? null
+                  : () => _cancelEditing(profile),
               child: Text(tr('ui.common.cancel')),
             ),
           ],

userfront/lib/main.dart

@@ -28,6 +28,7 @@ import 'core/i18n/locale_gate.dart';
 import 'core/i18n/locale_registry.dart';
 import 'core/i18n/locale_utils.dart';
 import 'core/i18n/toml_asset_loader.dart';
+import 'core/ui/toast_service.dart';
 import 'package:logging/logging.dart';
 import 'features/auth/presentation/consent_screen.dart';
 import 'i18n.dart';
@@ -370,6 +371,11 @@ class BaronSSOApp extends StatelessWidget {
       localizationsDelegates: delegates,
       supportedLocales: supportedLocales,
       locale: locale,
+      builder: (context, child) {
+        return Stack(
+          children: [if (child != null) child, const ToastViewport()],
+        );
+      },
       theme: ThemeData(
         colorScheme: ColorScheme.fromSeed(
           seedColor: const Color(0xFF1A1F2C), // Dark Navy/Black base