redesign app phase 3

lib/main.dart

@@ -9,7 +9,6 @@ import 'package:finamp/screens/interaction_settings_screen.dart';
 import 'package:finamp/services/finamp_settings_helper.dart';
 import 'package:finamp/services/finamp_user_helper.dart';
 import 'package:finamp/services/offline_listen_helper.dart';
-import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_downloader/flutter_downloader.dart';
@@ -46,6 +45,7 @@ import 'screens/user_selector.dart';
 import 'screens/view_selector.dart';
 import 'services/audio_service_helper.dart';
 import 'services/download_update_stream.dart';
+import 'services/download_support.dart';
 import 'services/downloads_helper.dart';
 import 'services/jellyfin_api_helper.dart';
 import 'services/locale_helper.dart';
@@ -123,7 +123,7 @@ Future<void> _setupDownloader() async {
   GetIt.instance.registerSingleton(DownloadUpdateStream());
   GetIt.instance<DownloadUpdateStream>().setupSendPort();
 
-  if (!_isDownloaderSupported) {
+  if (!isDownloaderSupported) {
     return;
   }
 
@@ -137,15 +137,6 @@ Future<void> _setupDownloader() async {
   FlutterDownloader.registerCallback(_DummyCallback.callback);
 }
 
-bool get _isDownloaderSupported {
-  if (kIsWeb) {
-    return false;
-  }
-
-  return defaultTargetPlatform == TargetPlatform.android ||
-      defaultTargetPlatform == TargetPlatform.iOS;
-}
-
 Future<void> setupHive() async {
   await Hive.initFlutter();
   Hive.registerAdapter(BaseItemDtoAdapter());
@@ -369,6 +360,19 @@ class Finamp extends StatelessWidget {
                     useMaterial3: true,
                     brightness: Brightness.dark,
                     colorScheme: darkColorScheme,
+                    scaffoldBackgroundColor: darkColorScheme.background,
+                    cardTheme: CardThemeData(
+                      color: darkColorScheme.surfaceVariant,
+                      elevation: 0,
+                      shape: RoundedRectangleBorder(
+                        borderRadius: BorderRadius.circular(28),
+                      ),
+                    ),
+                    appBarTheme: const AppBarTheme(
+                      backgroundColor: Colors.transparent,
+                      elevation: 0,
+                      scrolledUnderElevation: 0,
+                    ),
                   ),
                   themeMode: box.get("ThemeMode"),
                   localizationsDelegates: const [