added oled theme and theme presets

BalanceFlutter/lib/domain/appearance.dart

@@ -0,0 +1,15 @@
+/// Device-local appearance preferences; these never enter finance sync payloads.
+enum ColorPreset {
+  forest('forest', 'Лес', 0xff356859),
+  indigo('indigo', 'Индиго', 0xff4f46a5),
+  ocean('ocean', 'Океан', 0xff006b9a),
+  rose('rose', 'Роза', 0xff984563),
+  oled('oled', 'OLED — чёрный', 0xff51bda0);
+
+  const ColorPreset(this.id, this.label, this.seedArgb);
+  final String id, label;
+  final int seedArgb;
+
+  static ColorPreset fromId(String? id) =>
+      values.firstWhere((preset) => preset.id == id, orElse: () => forest);
+}

BalanceFlutter/lib/services/app_store.dart

@@ -7,6 +7,7 @@ import 'package:shared_preferences/shared_preferences.dart';
 import 'package:uuid/uuid.dart';
 
 import '../domain/finance.dart';
+import '../domain/appearance.dart';
 import 'storage.dart';
 import 'runtime_lock.dart';
 import 'sync_api.dart';
@@ -62,6 +63,7 @@ class AppStore extends ChangeNotifier with WidgetsBindingObserver {
   String serverUrl = '';
   String currency = 'RUB';
   String theme = 'system';
+  String themePreset = 'forest';
   AuthSession? session;
   String? sessionPersistenceWarning;
   String get email => session?.email ?? '';
@@ -121,6 +123,7 @@ class AppStore extends ChangeNotifier with WidgetsBindingObserver {
     serverUrl = _preferences!.getString('serverUrl') ?? serverUrl;
     currency = _preferences!.getString('currency') ?? currency;
     theme = _preferences!.getString('theme') ?? theme;
+    themePreset = ColorPreset.fromId(_preferences!.getString('themePreset')).id;
     _deviceId = _preferences!.getString('deviceId') ?? newId();
     await _preferences!.setString('deviceId', _deviceId);
     _storage ??= await LedgerStorage.open();
@@ -147,6 +150,7 @@ class AppStore extends ChangeNotifier with WidgetsBindingObserver {
     }
     currency = _preferences!.getString('currency') ?? 'RUB';
     theme = _preferences!.getString('theme') ?? 'system';
+    themePreset = ColorPreset.fromId(_preferences!.getString('themePreset')).id;
     _deviceId = _preferences!.getString('deviceId') ?? _deviceId;
     await _restoreSession();
     await _loadScope();
@@ -481,10 +485,26 @@ class AppStore extends ChangeNotifier with WidgetsBindingObserver {
     _notify();
   });
   Future<void> setTheme(String value) => _exclusive(() async {
+    if (!const ['system', 'light', 'dark'].contains(value)) {
+      throw ArgumentError('Неизвестный режим темы');
+    }
     theme = value;
     await _preferences!.setString('theme', value);
     _notify();
   });
+  Future<void> setThemePreset(String value) => _exclusive(() async {
+    if (!ColorPreset.values.any((preset) => preset.id == value)) {
+      throw ArgumentError('Неизвестный пресет');
+    }
+    await _preferences!.setString('themePreset', value);
+    themePreset = value;
+    if (value == ColorPreset.oled.id) {
+      await _preferences!.setString('theme', 'dark');
+      theme = 'dark';
+    }
+    _notify();
+  });
+
   Future<void> setServerUrl(String value) => _exclusive(() async {
     final normalized = value.trim().replaceAll(RegExp(r'/+$'), '');
     final uri = Uri.tryParse(normalized);

BalanceFlutter/lib/ui/app.dart

@@ -6,6 +6,8 @@ import 'package:intl/intl.dart';
 import 'package:file_selector/file_selector.dart';
 import 'package:share_plus/share_plus.dart';
 import '../domain/finance.dart';
+import '../domain/appearance.dart';
+import 'app_theme.dart';
 import '../services/app_store.dart';
 import 'design.dart';
 import 'editors.dart';
@@ -22,8 +24,14 @@ class BalanceApp extends StatelessWidget {
       locale: const Locale('ru'),
       supportedLocales: const [Locale('ru'), Locale('en')],
       localizationsDelegates: GlobalMaterialLocalizations.delegates,
-      theme: makeTheme(Brightness.light),
-      darkTheme: makeTheme(Brightness.dark),
+      theme: BalanceThemes.build(
+        Brightness.light,
+        ColorPreset.fromId(store.themePreset),
+      ),
+      darkTheme: BalanceThemes.build(
+        Brightness.dark,
+        ColorPreset.fromId(store.themePreset),
+      ),
       themeMode: store.theme == 'dark'
           ? ThemeMode.dark
           : store.theme == 'light'
@@ -34,28 +42,6 @@ class BalanceApp extends StatelessWidget {
           : const Scaffold(body: Center(child: CircularProgressIndicator())),
     ),
   );
-  ThemeData makeTheme(Brightness brightness) {
-    final scheme = ColorScheme.fromSeed(
-      seedColor: const Color(0xff356859),
-      brightness: brightness,
-    );
-    return ThemeData(
-      useMaterial3: true,
-      fontFamily: 'BalanceRoboto',
-      colorScheme: scheme,
-      scaffoldBackgroundColor: scheme.surface,
-      inputDecorationTheme: const InputDecorationTheme(
-        border: OutlineInputBorder(),
-      ),
-      cardTheme: CardThemeData(
-        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(24)),
-      ),
-      appBarTheme: AppBarTheme(
-        backgroundColor: scheme.surface,
-        centerTitle: false,
-      ),
-    );
-  }
 }
 
 class BalanceShell extends StatefulWidget {
@@ -1105,6 +1091,7 @@ class _BalanceShellState extends State<BalanceShell> {
           ),
           const SizedBox(height: 16),
           DropdownButtonFormField<String>(
+            key: ValueKey('theme-mode-${store.theme}'),
             initialValue: store.theme,
             decoration: const InputDecoration(labelText: 'Тема'),
             items: const [
@@ -1116,6 +1103,45 @@ class _BalanceShellState extends State<BalanceShell> {
               if (v != null) run(() => store.setTheme(v));
             },
           ),
+          const SizedBox(height: 20),
+          Text(
+            'Цветовой пресет',
+            style: Theme.of(context).textTheme.titleSmall,
+          ),
+          const SizedBox(height: 10),
+          Wrap(
+            spacing: 8,
+            runSpacing: 8,
+            children: ColorPreset.values
+                .map(
+                  (preset) => ChoiceChip(
+                    label: Text(preset.label),
+                    avatar: CircleAvatar(
+                      radius: 9,
+                      backgroundColor: preset == ColorPreset.oled
+                          ? Colors.black
+                          : Color(preset.seedArgb),
+                      child: preset == ColorPreset.oled
+                          ? const Icon(
+                              Icons.nightlight_round,
+                              size: 13,
+                              color: Colors.white,
+                            )
+                          : null,
+                    ),
+                    selected: store.themePreset == preset.id,
+                    onSelected: (_) =>
+                        run(() => store.setThemePreset(preset.id)),
+                  ),
+                )
+                .toList(),
+          ),
+          if (store.themePreset == 'oled') ...[
+            const SizedBox(height: 12),
+            const Text(
+              'OLED: чистый чёрный фон #000000 в тёмном режиме. При выборе пресета тёмная тема включается автоматически. Можно затем выбрать системный режим.',
+            ),
+          ],
           const SizedBox(height: 12),
           Text(
             'Валюта задаёт формат сумм. Конвертация валют не выполняется.',
@@ -1288,7 +1314,7 @@ class _BalanceShellState extends State<BalanceShell> {
                 onPressed: () => showAboutDialog(
                   context: context,
                   applicationName: 'Баланс',
-                  applicationVersion: '4.0.0',
+                  applicationVersion: '4.1.0',
                   applicationIcon: const Icon(
                     Icons.account_balance_wallet_outlined,
                     size: 40,

BalanceFlutter/lib/ui/app_theme.dart

@@ -0,0 +1,65 @@
+import 'package:flutter/material.dart';
+import '../domain/appearance.dart';
+
+class BalanceThemes {
+  static ThemeData build(Brightness brightness, ColorPreset preset) {
+    final oled = brightness == Brightness.dark && preset == ColorPreset.oled;
+    var scheme = ColorScheme.fromSeed(
+      seedColor: Color(preset.seedArgb),
+      brightness: brightness,
+    );
+    if (oled) {
+      scheme = scheme.copyWith(
+        surface: Colors.black,
+        surfaceDim: Colors.black,
+        surfaceBright: Colors.black,
+        surfaceContainerLowest: Colors.black,
+        surfaceContainerLow: Colors.black,
+        surfaceContainer: Colors.black,
+        surfaceContainerHigh: Colors.black,
+        surfaceContainerHighest: Colors.black,
+        surfaceTint: Colors.transparent,
+        primaryContainer: Colors.black,
+        onPrimaryContainer: scheme.onSurface,
+        secondaryContainer: const Color(0xff171b19),
+        outlineVariant: const Color(0xff303633),
+      );
+    }
+    return ThemeData(
+      useMaterial3: true,
+      fontFamily: 'BalanceRoboto',
+      colorScheme: scheme,
+      scaffoldBackgroundColor: scheme.surface,
+      canvasColor: scheme.surface,
+      applyElevationOverlayColor: !oled,
+      inputDecorationTheme: const InputDecorationTheme(
+        border: OutlineInputBorder(),
+      ),
+      cardTheme: CardThemeData(
+        surfaceTintColor: oled ? Colors.transparent : null,
+        shape: RoundedRectangleBorder(
+          borderRadius: BorderRadius.circular(24),
+          side: oled
+              ? BorderSide(color: scheme.outlineVariant)
+              : BorderSide.none,
+        ),
+      ),
+      appBarTheme: AppBarTheme(
+        backgroundColor: scheme.surface,
+        surfaceTintColor: oled ? Colors.transparent : null,
+        centerTitle: false,
+      ),
+      navigationBarTheme: NavigationBarThemeData(
+        backgroundColor: oled ? Colors.black : null,
+        surfaceTintColor: oled ? Colors.transparent : null,
+      ),
+      navigationRailTheme: NavigationRailThemeData(
+        backgroundColor: oled ? Colors.black : null,
+      ),
+      dialogTheme: DialogThemeData(
+        backgroundColor: oled ? Colors.black : null,
+        surfaceTintColor: oled ? Colors.transparent : null,
+      ),
+    );
+  }
+}