diff --git a/lib/api/api_request.dart b/lib/api/api_request.dart
deleted file mode 100644
index 2cdf97c..0000000
--- a/lib/api/api_request.dart
+++ /dev/null
@@ -1 +0,0 @@
-class ApiRequest {}
diff --git a/lib/api/errors/error_mapper.dart b/lib/api/errors/error_mapper.dart
index 7fb4a9d..9cafa3a 100644
--- a/lib/api/errors/error_mapper.dart
+++ b/lib/api/errors/error_mapper.dart
@@ -6,6 +6,7 @@ import 'package:http/http.dart' as http;
 import 'package:nextcloud/nextcloud.dart';
 
 import '../api_error.dart';
+import '../http_errors.dart';
 import '../marianumcloud/talk/talk_error.dart';
 import 'app_exception.dart';
 import 'auth_exception.dart';
@@ -59,9 +60,8 @@ AppException? _dioToAppException(DioException error) {
 /// status plus a trimmed body preview (same format as the Talk API errors).
 AppException _dynamiteToAppException(DynamiteApiException error) {
   final status = error.statusCode;
-  final body = error.body.replaceAll(RegExp(r'\s+'), ' ').trim();
-  final preview = body.length > 500 ? '${body.substring(0, 500)}…' : body;
-  final detail = body.isEmpty ? 'HTTP $status' : 'HTTP $status body=$preview';
+  final preview = previewBody(error.body);
+  final detail = preview.isEmpty ? 'HTTP $status' : 'HTTP $status body=$preview';
   switch (status) {
     case 401:
       return AuthException.unauthorized(technicalDetails: detail);
diff --git a/lib/api/http_errors.dart b/lib/api/http_errors.dart
new file mode 100644
index 0000000..f45f770
--- /dev/null
+++ b/lib/api/http_errors.dart
@@ -0,0 +1,53 @@
+import 'dart:async';
+import 'dart:io';
+
+import 'package:http/http.dart' as http;
+
+import 'errors/auth_exception.dart';
+import 'errors/network_exception.dart';
+import 'errors/not_found_exception.dart';
+import 'errors/server_exception.dart';
+
+/// Runs [send] and converts transport-level failures (socket/timeout/client
+/// errors) into a [NetworkException] tagged with [label] (e.g. `Talk <uri>`).
+/// Passes through whatever [send] produces, including `null` for the base-class
+/// request hooks that may skip the call.
+Future<http.Response?> sendGuarded(
+  String label,
+  Future<http.Response>? Function() send,
+) async {
+  try {
+    return await send();
+  } on SocketException catch (e) {
+    throw NetworkException(technicalDetails: '$label: ${e.message}');
+  } on TimeoutException catch (e) {
+    throw NetworkException.timeout(technicalDetails: '$label: $e');
+  } on http.ClientException catch (e) {
+    throw NetworkException(technicalDetails: '$label: ${e.message}');
+  }
+}
+
+/// Collapses whitespace and caps an HTTP error body at 500 chars so it can be
+/// embedded in an [AppException]'s technical details without dumping headers.
+String previewBody(String body) {
+  final collapsed = body.replaceAll(RegExp(r'\s+'), ' ').trim();
+  return collapsed.length > 500 ? '${collapsed.substring(0, 500)}…' : collapsed;
+}
+
+/// Builds a `<label> -> HTTP <status>[ body=<preview>]` technical detail line.
+String httpErrorDetail(String label, String body, int status) {
+  final preview = previewBody(body);
+  return preview.isEmpty
+      ? '$label -> HTTP $status'
+      : '$label -> HTTP $status body=$preview';
+}
+
+/// Throws the [AppException] matching a non-2xx HTTP [status], carrying
+/// [detail] as technical details: 401/403 map to auth errors, 404 to
+/// not-found, everything else to a generic server error.
+Never throwForStatus(int status, String detail) {
+  if (status == 401) throw AuthException.unauthorized(technicalDetails: detail);
+  if (status == 403) throw AuthException.forbidden(technicalDetails: detail);
+  if (status == 404) throw NotFoundException(technicalDetails: detail);
+  throw ServerException(statusCode: status, technicalDetails: detail);
+}
diff --git a/lib/api/marianumcloud/cloud_users/cloud_users_actions.dart b/lib/api/marianumcloud/cloud_users/cloud_users_actions.dart
index 6d0203d..abd85c4 100644
--- a/lib/api/marianumcloud/cloud_users/cloud_users_actions.dart
+++ b/lib/api/marianumcloud/cloud_users/cloud_users_actions.dart
@@ -1,18 +1,13 @@
-import 'dart:async';
 import 'dart:convert';
 import 'dart:developer';
-import 'dart:io';
 import 'dart:typed_data';
 
 import 'package:http/http.dart' as http;
 
 import '../../../model/account_data.dart';
 import '../../../model/endpoint_data.dart';
-import '../../errors/auth_exception.dart';
-import '../../errors/network_exception.dart';
-import '../../errors/not_found_exception.dart';
 import '../../errors/parse_exception.dart';
-import '../../errors/server_exception.dart';
+import '../../http_errors.dart';
 import '../nextcloud_ocs.dart';
 
 /// Mix of two Nextcloud surfaces:
@@ -42,30 +37,17 @@ Future<http.Response> _send(
 ) async {
   final headers = NextcloudOcs.headers();
 
-  final http.Response response;
-  try {
-    response = await perform(uri, headers);
-  } on SocketException catch (e) {
-    throw NetworkException(technicalDetails: 'Cloud $uri: ${e.message}');
-  } on TimeoutException catch (e) {
-    throw NetworkException.timeout(technicalDetails: 'Cloud $uri: $e');
-  } on http.ClientException catch (e) {
-    throw NetworkException(technicalDetails: 'Cloud $uri: ${e.message}');
-  }
+  final response = (await sendGuarded(
+    'Cloud $uri',
+    () => perform(uri, headers),
+  ))!;
 
   final status = response.statusCode;
   if (status >= 200 && status < 300) return response;
 
-  final body = response.body.replaceAll(RegExp(r'\s+'), ' ').trim();
-  final preview = body.length > 500 ? '${body.substring(0, 500)}…' : body;
-  final detail = body.isEmpty
-      ? 'Cloud $uri -> HTTP $status'
-      : 'Cloud $uri -> HTTP $status body=$preview';
+  final detail = httpErrorDetail('Cloud $uri', response.body, status);
   log(detail);
-  if (status == 401) throw AuthException.unauthorized(technicalDetails: detail);
-  if (status == 403) throw AuthException.forbidden(technicalDetails: detail);
-  if (status == 404) throw NotFoundException(technicalDetails: detail);
-  throw ServerException(statusCode: status, technicalDetails: detail);
+  throwForStatus(status, detail);
 }
 
 class SetUserAvatar {
diff --git a/lib/api/marianumcloud/talk/chat/long_poll_chat.dart b/lib/api/marianumcloud/talk/chat/long_poll_chat.dart
index ad3bcd3..6b285b1 100644
--- a/lib/api/marianumcloud/talk/chat/long_poll_chat.dart
+++ b/lib/api/marianumcloud/talk/chat/long_poll_chat.dart
@@ -1,10 +1,7 @@
-import 'dart:async';
-import 'dart:io';
-
 import 'package:http/http.dart' as http;
 
-import '../../../errors/network_exception.dart';
 import '../../../errors/server_exception.dart';
+import '../../../http_errors.dart';
 import '../../nextcloud_ocs.dart';
 import 'get_chat_params.dart';
 import 'get_chat_response.dart';
@@ -40,18 +37,12 @@ class LongPollChat {
     );
     final headers = NextcloudOcs.headers();
 
-    final http.Response response;
-    try {
-      response = await http
+    final response = (await sendGuarded(
+      'LongPollChat $uri',
+      () => http
           .get(uri, headers: headers)
-          .timeout(Duration(seconds: timeoutSeconds + 15));
-    } on TimeoutException catch (e) {
-      throw NetworkException.timeout(technicalDetails: 'LongPollChat $uri: $e');
-    } on SocketException catch (e) {
-      throw NetworkException(technicalDetails: 'LongPollChat $uri: ${e.message}');
-    } on http.ClientException catch (e) {
-      throw NetworkException(technicalDetails: 'LongPollChat $uri: ${e.message}');
-    }
+          .timeout(Duration(seconds: timeoutSeconds + 15)),
+    ))!;
 
     final status = response.statusCode;
     if (status == 304) return null;
diff --git a/lib/api/marianumcloud/talk/talk_api.dart b/lib/api/marianumcloud/talk/talk_api.dart
index 44bc16f..d8b4e6a 100644
--- a/lib/api/marianumcloud/talk/talk_api.dart
+++ b/lib/api/marianumcloud/talk/talk_api.dart
@@ -1,29 +1,20 @@
-import 'dart:async';
 import 'dart:developer';
-import 'dart:io';
 
 import 'package:http/http.dart' as http;
 
 import '../../api_params.dart';
-import '../../api_request.dart';
 import '../../api_response.dart';
-import '../../errors/auth_exception.dart';
 import '../../errors/network_exception.dart';
-import '../../errors/not_found_exception.dart';
 import '../../errors/parse_exception.dart';
-import '../../errors/server_exception.dart';
+import '../../http_errors.dart';
 import '../nextcloud_ocs.dart';
 
-enum TalkApiMethod { get, post, put, delete }
-
-abstract class TalkApi<T extends ApiResponse?> extends ApiRequest {
+abstract class TalkApi<T extends ApiResponse?> {
   String path;
   ApiParams? body;
   Map<String, String>? headers;
   Map<String, dynamic>? getParameters;
 
-  http.Response? response;
-
   TalkApi(this.path, this.body, {this.headers, this.getParameters});
 
   Future<http.Response>? request(
@@ -40,22 +31,15 @@ abstract class TalkApi<T extends ApiResponse?> extends ApiRequest {
     );
     final mergedHeaders = {...NextcloudOcs.headers(), ...?headers};
 
-    final http.Response data;
-    try {
-      final raw = await request(endpoint, body, mergedHeaders);
-      if (raw == null) {
-        throw const NetworkException(
-          userMessage: 'Keine Antwort vom Talk-Server erhalten.',
-          technicalDetails: 'Talk request returned null',
-        );
-      }
-      data = raw;
-    } on SocketException catch (e) {
-      throw NetworkException(technicalDetails: 'Talk $endpoint: ${e.message}');
-    } on TimeoutException catch (e) {
-      throw NetworkException.timeout(technicalDetails: 'Talk $endpoint: $e');
-    } on http.ClientException catch (e) {
-      throw NetworkException(technicalDetails: 'Talk $endpoint: ${e.message}');
+    final data = await sendGuarded(
+      'Talk $endpoint',
+      () => request(endpoint, body, mergedHeaders),
+    );
+    if (data == null) {
+      throw const NetworkException(
+        userMessage: 'Keine Antwort vom Talk-Server erhalten.',
+        technicalDetails: 'Talk request returned null',
+      );
     }
 
     final status = data.statusCode;
@@ -63,20 +47,9 @@ abstract class TalkApi<T extends ApiResponse?> extends ApiRequest {
       // Talk's OCS errors carry the real reason in the body (expired session,
       // removed participant, ...); include a trimmed preview so the dialog and
       // logs surface the cause instead of just the bare status code.
-      final body = data.body.replaceAll(RegExp(r'\s+'), ' ').trim();
-      final preview = body.length > 500 ? '${body.substring(0, 500)}…' : body;
-      final detail = body.isEmpty
-          ? 'Talk $endpoint -> HTTP $status'
-          : 'Talk $endpoint -> HTTP $status body=$preview';
+      final detail = httpErrorDetail('Talk $endpoint', data.body, status);
       log(detail);
-      if (status == 401) {
-        throw AuthException.unauthorized(technicalDetails: detail);
-      }
-      if (status == 403) {
-        throw AuthException.forbidden(technicalDetails: detail);
-      }
-      if (status == 404) throw NotFoundException(technicalDetails: detail);
-      throw ServerException(statusCode: status, technicalDetails: detail);
+      throwForStatus(status, detail);
     }
 
     try {
diff --git a/lib/api/marianumcloud/webdav/webdav_api.dart b/lib/api/marianumcloud/webdav/webdav_api.dart
index 5916761..76bbafc 100644
--- a/lib/api/marianumcloud/webdav/webdav_api.dart
+++ b/lib/api/marianumcloud/webdav/webdav_api.dart
@@ -2,10 +2,9 @@ import 'package:nextcloud/nextcloud.dart';
 
 import '../../../model/account_data.dart';
 import '../../../model/endpoint_data.dart';
-import '../../api_request.dart';
 import '../../api_response.dart';
 
-abstract class WebdavApi<T> extends ApiRequest {
+abstract class WebdavApi<T> {
   T genericParams;
 
   WebdavApi(this.genericParams) {
diff --git a/lib/api/mhsl/mhsl_api.dart b/lib/api/mhsl/mhsl_api.dart
index 80b79bb..8091d33 100644
--- a/lib/api/mhsl/mhsl_api.dart
+++ b/lib/api/mhsl/mhsl_api.dart
@@ -1,21 +1,16 @@
-import 'dart:async';
 import 'dart:convert';
-import 'dart:io';
 
 import 'package:http/http.dart' as http;
-import 'package:jiffy/jiffy.dart';
 
-import '../api_request.dart';
 import '../errors/network_exception.dart';
 import '../errors/parse_exception.dart';
 import '../errors/server_exception.dart';
+import '../http_errors.dart';
 
-abstract class MhslApi<T> extends ApiRequest {
+abstract class MhslApi<T> {
   String subpath;
   MhslApi(this.subpath);
 
-  http.Response? response;
-
   Future<http.Response>? request(Uri uri);
   T assemble(String raw);
 
@@ -24,22 +19,12 @@ abstract class MhslApi<T> extends ApiRequest {
       'https://mhsl.eu/marianum/marianummobile/$subpath',
     );
 
-    final http.Response data;
-    try {
-      final raw = await request(endpoint);
-      if (raw == null) {
-        throw const NetworkException(
-          userMessage: 'Keine Antwort vom MHSL-Dienst erhalten.',
-          technicalDetails: 'mhsl request returned null',
-        );
-      }
-      data = raw;
-    } on SocketException catch (e) {
-      throw NetworkException(technicalDetails: 'mhsl $subpath: ${e.message}');
-    } on TimeoutException catch (e) {
-      throw NetworkException.timeout(technicalDetails: 'mhsl $subpath: $e');
-    } on http.ClientException catch (e) {
-      throw NetworkException(technicalDetails: 'mhsl $subpath: ${e.message}');
+    final data = await sendGuarded('mhsl $subpath', () => request(endpoint));
+    if (data == null) {
+      throw const NetworkException(
+        userMessage: 'Keine Antwort vom MHSL-Dienst erhalten.',
+        technicalDetails: 'mhsl request returned null',
+      );
     }
 
     if (data.statusCode > 299) {
@@ -55,8 +40,4 @@ abstract class MhslApi<T> extends ApiRequest {
       throw ParseException(technicalDetails: 'mhsl $subpath assemble: $e');
     }
   }
-
-  static String dateTimeToJson(DateTime time) =>
-      Jiffy.parseFromDateTime(time).format(pattern: 'yyyy-MM-dd HH:mm:ss');
-  static DateTime dateTimeFromJson(String time) => DateTime.parse(time);
 }
diff --git a/lib/app.dart b/lib/app.dart
index 7727c36..8ce0b4f 100644
--- a/lib/app.dart
+++ b/lib/app.dart
@@ -256,9 +256,7 @@ class _AppState extends State<App> with WidgetsBindingObserver {
 
       if (totalTabs != _knownTotalTabs) {
         var targetIndex = currentIndex;
-        if (_userOnLastTab) {
-          targetIndex = totalTabs - 1;
-        } else if (currentIndex >= totalTabs) {
+        if (_userOnLastTab || currentIndex >= totalTabs) {
           targetIndex = totalTabs - 1;
         }
         // Replace the controller atomically: a stale index past the new
diff --git a/lib/state/app/infrastructure/data_loader/data_loader.dart b/lib/state/app/infrastructure/data_loader/data_loader.dart
deleted file mode 100644
index 8b1dc93..0000000
--- a/lib/state/app/infrastructure/data_loader/data_loader.dart
+++ /dev/null
@@ -1,45 +0,0 @@
-import 'dart:convert';
-import 'dart:developer';
-
-import 'package:dio/dio.dart';
-
-abstract class DataLoader<TResult> {
-  final Dio dio;
-  DataLoader(this.dio) {
-    dio.options.connectTimeout = const Duration(seconds: 10);
-    dio.options.sendTimeout = const Duration(seconds: 30);
-    dio.options.receiveTimeout = const Duration(seconds: 30);
-  }
-
-  Future<TResult> run() async {
-    final response = await fetch();
-    try {
-      return assemble(
-        DataLoaderResult(
-          json: jsonDecode(response.data!),
-          headers: response.headers.map.map(
-            (key, value) => MapEntry(key, value.join(';')),
-          ),
-        ),
-      );
-    } catch (e, stack) {
-      log('DataLoader assemble failed', error: e, stackTrace: stack);
-      rethrow;
-    }
-  }
-
-  Future<Response<String>> fetch();
-  TResult assemble(DataLoaderResult data);
-}
-
-class DataLoaderResult {
-  final dynamic json;
-  final Map<String, String> headers;
-
-  Map<String, dynamic> asMap() => json as Map<String, dynamic>;
-  List<dynamic> asList() => json as List<dynamic>;
-  List<Map<String, dynamic>> asListOfMaps() =>
-      asList().map((e) => e as Map<String, dynamic>).toList();
-
-  DataLoaderResult({required this.json, required this.headers});
-}
diff --git a/lib/state/app/infrastructure/loadable_state/loadable_state.dart b/lib/state/app/infrastructure/loadable_state/loadable_state.dart
index 14cb551..84dd97e 100644
--- a/lib/state/app/infrastructure/loadable_state/loadable_state.dart
+++ b/lib/state/app/infrastructure/loadable_state/loadable_state.dart
@@ -19,12 +19,5 @@ abstract class LoadableState<TState> with _$LoadableState<TState> {
     String? statusText,
   }) = _LoadableState<TState>;
 
-  bool _hasError() => error != null;
-  bool _hasData() => data != null;
-
-  bool showPrimaryLoading() => isLoading && !_hasData();
-  bool showBackgroundLoading() => isLoading && _hasData();
-  bool showErrorBar() => _hasError() && _hasData();
-  bool showError() => _hasError() && !_hasData();
-  bool showContent() => _hasData();
+  bool showContent() => data != null;
 }
diff --git a/lib/utils/downloads/download_manager.dart b/lib/utils/downloads/download_manager.dart
index e485509..23284dc 100644
--- a/lib/utils/downloads/download_manager.dart
+++ b/lib/utils/downloads/download_manager.dart
@@ -36,7 +36,6 @@ class DownloadManager {
 
   final Map<String, DownloadJob> _jobs = {}; // keyed by remotePath
   final Map<String, DownloadJob> _byTaskId = {};
-  final Map<String, bd.DownloadTask> _taskById = {};
 
   /// All jobs the user should currently see in the downloads tray/overview:
   /// everything that is in progress or finished-but-not-yet-opened (failed
@@ -134,7 +133,6 @@ class DownloadManager {
     )..taskId = task.taskId;
     _jobs[remotePath] = job;
     _byTaskId[task.taskId] = job;
-    _taskById[task.taskId] = task;
     _refreshVisible();
 
     final ok = await bd.FileDownloader().enqueue(task);
@@ -217,10 +215,7 @@ class DownloadManager {
         job.status.value = const DownloadCancelled();
       }
       _jobs.remove(job.remotePath);
-      if (taskId != null) {
-        _byTaskId.remove(taskId);
-        _taskById.remove(taskId);
-      }
+      if (taskId != null) _byTaskId.remove(taskId);
       scheduleMicrotask(job.dispose);
     }
     _refreshVisible();
@@ -314,10 +309,7 @@ class DownloadManager {
   void _remove(DownloadJob job) {
     _jobs.remove(job.remotePath);
     final taskId = job.taskId;
-    if (taskId != null) {
-      _byTaskId.remove(taskId);
-      _taskById.remove(taskId);
-    }
+    if (taskId != null) _byTaskId.remove(taskId);
     _refreshVisible();
     scheduleMicrotask(job.dispose);
   }
diff --git a/lib/view/pages/files/widgets/file_element.dart b/lib/view/pages/files/widgets/file_element.dart
index 15dc1bb..f280b89 100644
--- a/lib/view/pages/files/widgets/file_element.dart
+++ b/lib/view/pages/files/widgets/file_element.dart
@@ -171,21 +171,18 @@ class _FileElementState extends State<FileElement>
     );
   }
 
-  Future<void> _delete() async {
+  void _delete() {
     if (guardDemoAction(context)) return;
-    await showDialog<void>(
-      context: context,
-      builder: (context) => ConfirmDialog(
-        title: 'Element löschen?',
-        content: 'Das Element wird unwiederruflich gelöscht.',
-        confirmButton: 'Löschen',
-        onConfirmAsync: () async {
-          final webdav = await WebdavApi.webdav;
-          await webdav.delete(PathUri.parse(widget.file.path));
-          widget.refetch();
-        },
-      ),
-    );
+    ConfirmDialog(
+      title: 'Element löschen?',
+      content: 'Das Element wird unwiederruflich gelöscht.',
+      confirmButton: 'Löschen',
+      onConfirmAsync: () async {
+        final webdav = await WebdavApi.webdav;
+        await webdav.delete(PathUri.parse(widget.file.path));
+        widget.refetch();
+      },
+    ).asDialog(context);
   }
 
   void _showActionSheet() {
diff --git a/lib/view/pages/settings/chat_background_settings_page.dart b/lib/view/pages/settings/chat_background_settings_page.dart
index bee5fb8..0012913 100644
--- a/lib/view/pages/settings/chat_background_settings_page.dart
+++ b/lib/view/pages/settings/chat_background_settings_page.dart
@@ -86,20 +86,11 @@ class ChatBackgroundSettingsPage extends StatelessWidget {
                   trailing: DropdownButton<ChatBackgroundType>(
                     value: s.type,
                     icon: const Icon(Icons.arrow_drop_down),
-                    items: ChatBackgroundType.values
-                        .map(
-                          (e) => DropdownMenuItem<ChatBackgroundType>(
-                            value: e,
-                            child: Row(
-                              children: [
-                                Icon(_typeIcon(e)),
-                                const SizedBox(width: 10),
-                                Text(_typeLabel(e)),
-                              ],
-                            ),
-                          ),
-                        )
-                        .toList(),
+                    items: _iconDropdownItems(
+                      ChatBackgroundType.values,
+                      _typeIcon,
+                      _typeLabel,
+                    ),
                     onChanged: (e) => _onTypeChanged(context, settings, e!),
                   ),
                 ),
@@ -142,20 +133,11 @@ class ChatBackgroundSettingsPage extends StatelessWidget {
                     trailing: DropdownButton<ChatBackgroundFit>(
                       value: s.fit,
                       icon: const Icon(Icons.arrow_drop_down),
-                      items: ChatBackgroundFit.values
-                          .map(
-                            (e) => DropdownMenuItem<ChatBackgroundFit>(
-                              value: e,
-                              child: Row(
-                                children: [
-                                  Icon(_fitIcon(e)),
-                                  const SizedBox(width: 10),
-                                  Text(_fitLabel(e)),
-                                ],
-                              ),
-                            ),
-                          )
-                          .toList(),
+                      items: _iconDropdownItems(
+                        ChatBackgroundFit.values,
+                        _fitIcon,
+                        _fitLabel,
+                      ),
                       onChanged: (e) {
                         Haptics.selection();
                         settings.val(write: true).chatBackgroundSettings.fit =
@@ -280,6 +262,27 @@ class ChatBackgroundSettingsPage extends StatelessWidget {
     cs.type = ChatBackgroundType.color;
   }
 
+  /// Dropdown menu items rendered as an icon + label row, shared by the source
+  /// and fill-mode pickers.
+  static List<DropdownMenuItem<T>> _iconDropdownItems<T>(
+    List<T> values,
+    IconData Function(T) icon,
+    String Function(T) label,
+  ) => values
+      .map(
+        (e) => DropdownMenuItem<T>(
+          value: e,
+          child: Row(
+            children: [
+              Icon(icon(e)),
+              const SizedBox(width: 10),
+              Text(label(e)),
+            ],
+          ),
+        ),
+      )
+      .toList();
+
   IconData _typeIcon(ChatBackgroundType type) => switch (type) {
     ChatBackgroundType.pattern => Icons.texture_outlined,
     ChatBackgroundType.image => Icons.image_outlined,
@@ -330,7 +333,6 @@ class _Preview extends StatelessWidget {
               crossAxisAlignment: CrossAxisAlignment.start,
               children: [
                 _bubble(
-                  context,
                   alignment: Alignment.centerLeft,
                   color: remoteColor,
                   text: 'Wie gefällt dir der neue Hintergrund?',
@@ -338,7 +340,6 @@ class _Preview extends StatelessWidget {
                 ),
                 const SizedBox(height: 8),
                 _bubble(
-                  context,
                   alignment: Alignment.centerRight,
                   color: selfColor,
                   text: 'Sieht richtig gut aus! 🎉',
@@ -352,8 +353,7 @@ class _Preview extends StatelessWidget {
     );
   }
 
-  Widget _bubble(
-    BuildContext context, {
+  Widget _bubble({
     required Alignment alignment,
     required Color color,
     required String text,
diff --git a/lib/view/pages/talk/chat_view.dart b/lib/view/pages/talk/chat_view.dart
index a23d7f3..b11a7ad 100644
--- a/lib/view/pages/talk/chat_view.dart
+++ b/lib/view/pages/talk/chat_view.dart
@@ -245,7 +245,6 @@ class _ChatViewState extends State<ChatView> with RouteAware {
         lastDate = elementDate;
         messages.add(
           ChatBubble(
-            context: context,
             isSender: false,
             bubbleData: GetChatResponseObject.getDateDummy(element.timestamp),
             chatData: widget.room,
@@ -265,7 +264,6 @@ class _ChatViewState extends State<ChatView> with RouteAware {
 
       messages.add(
         ChatBubble(
-          context: context,
           isSender:
               element.actorId == widget.selfId &&
               (element.messageType ==
@@ -287,7 +285,6 @@ class _ChatViewState extends State<ChatView> with RouteAware {
       messages.insert(
         0,
         ChatBubble(
-          context: context,
           isSender: false,
           bubbleData: GetChatResponseObject.getTextDummy(
             'Zurzeit können in dieser App nur die letzten 200 vergangenen Nachrichten angezeigt werden. '
diff --git a/lib/view/pages/talk/data/chat_bubble_styles.dart b/lib/view/pages/talk/data/chat_bubble_styles.dart
index 3098cc0..c91086b 100644
--- a/lib/view/pages/talk/data/chat_bubble_styles.dart
+++ b/lib/view/pages/talk/data/chat_bubble_styles.dart
@@ -24,29 +24,23 @@ class ChatBubbleStyles {
     alignment: Alignment.center,
   );
 
-  BubbleStyle getRemoteStyle(bool seamless) {
-    var color = AppTheme.isDarkMode(context)
+  BubbleStyle getRemoteStyle() => BubbleStyle(
+    nip: BubbleNip.leftTop,
+    color: AppTheme.isDarkMode(context)
         ? const Color(0xff202c33)
-        : Colors.white;
-    return BubbleStyle(
-      nip: BubbleNip.leftTop,
-      color: seamless ? Colors.transparent : color,
-      elevation: seamless ? 0 : 1,
-      margin: const BubbleEdges.only(bottom: 10, left: 10, right: 50),
-      alignment: Alignment.topLeft,
-    );
-  }
+        : Colors.white,
+    elevation: 1,
+    margin: const BubbleEdges.only(bottom: 10, left: 10, right: 50),
+    alignment: Alignment.topLeft,
+  );
 
-  BubbleStyle getSelfStyle(bool seamless) {
-    var color = AppTheme.isDarkMode(context)
+  BubbleStyle getSelfStyle() => BubbleStyle(
+    nip: BubbleNip.rightBottom,
+    color: AppTheme.isDarkMode(context)
         ? const Color(0xff005c4b)
-        : const Color(0xffd3d3d3);
-    return BubbleStyle(
-      nip: BubbleNip.rightBottom,
-      color: seamless ? Colors.transparent : color,
-      elevation: seamless ? 0 : 1,
-      margin: const BubbleEdges.only(bottom: 10, right: 10, left: 50),
-      alignment: Alignment.topRight,
-    );
-  }
+        : const Color(0xffd3d3d3),
+    elevation: 1,
+    margin: const BubbleEdges.only(bottom: 10, right: 10, left: 50),
+    alignment: Alignment.topRight,
+  );
 }
diff --git a/lib/view/pages/talk/widgets/answer_reference.dart b/lib/view/pages/talk/widgets/answer_reference.dart
index a1c4e27..cded6ca 100644
--- a/lib/view/pages/talk/widgets/answer_reference.dart
+++ b/lib/view/pages/talk/widgets/answer_reference.dart
@@ -5,11 +5,9 @@ import '../../../../api/marianumcloud/talk/chat/rich_object_string_processor.dar
 import '../data/chat_bubble_styles.dart';
 
 class AnswerReference extends StatelessWidget {
-  final BuildContext context;
   final GetChatResponseObject referenceMessage;
   final String? selfId;
   const AnswerReference({
-    required this.context,
     required this.referenceMessage,
     required this.selfId,
     super.key,
@@ -20,8 +18,8 @@ class AnswerReference extends StatelessWidget {
     final style = ChatBubbleStyles(context);
     final isSelf = referenceMessage.actorId == selfId;
     final accent = isSelf
-        ? style.getSelfStyle(false).color!.withGreen(200)
-        : style.getRemoteStyle(false).color!.withWhite(200);
+        ? style.getSelfStyle().color!.withGreen(200)
+        : style.getRemoteStyle().color!.withWhite(200);
     return DecoratedBox(
       decoration: BoxDecoration(
         color: accent.withValues(alpha: 0.2),
diff --git a/lib/view/pages/talk/widgets/chat_bubble.dart b/lib/view/pages/talk/widgets/chat_bubble.dart
index a498eaf..55ffed2 100644
--- a/lib/view/pages/talk/widgets/chat_bubble.dart
+++ b/lib/view/pages/talk/widgets/chat_bubble.dart
@@ -23,7 +23,6 @@ import 'highlighted_linkify.dart';
 enum SearchHighlight { none, secondary, active }
 
 class ChatBubble extends StatefulWidget {
-  final BuildContext context;
   final bool isSender;
   final GetChatResponseObject bubbleData;
   final GetRoomResponseObject chatData;
@@ -40,7 +39,6 @@ class ChatBubble extends StatefulWidget {
   final SearchHighlight matchHighlight;
 
   const ChatBubble({
-    required this.context,
     required this.isSender,
     required this.bubbleData,
     required this.chatData,
@@ -123,8 +121,8 @@ class _ChatBubbleState extends State<ChatBubble>
       base = styles.getSystemStyle();
     } else {
       base = widget.isSender
-          ? styles.getSelfStyle(false)
-          : styles.getRemoteStyle(false);
+          ? styles.getSelfStyle()
+          : styles.getRemoteStyle();
     }
     switch (widget.matchHighlight) {
       case SearchHighlight.none:
@@ -366,7 +364,6 @@ class _BubbleContent extends StatelessWidget {
                   bubbleData.messageType ==
                       GetRoomResponseObjectMessageType.comment) ...[
                 AnswerReference(
-                  context: context,
                   referenceMessage: parent!,
                   selfId: selfId,
                 ),
diff --git a/lib/view/pages/talk/widgets/chat_textfield.dart b/lib/view/pages/talk/widgets/chat_textfield.dart
index 0cb8dc5..815e8eb 100644
--- a/lib/view/pages/talk/widgets/chat_textfield.dart
+++ b/lib/view/pages/talk/widgets/chat_textfield.dart
@@ -263,7 +263,6 @@ class _ChatTextfieldState extends State<ChatTextfield> {
           children: [
             Expanded(
               child: AnswerReference(
-                context: context,
                 referenceMessage: referenceMessage,
                 selfId: widget.selfId,
               ),
diff --git a/lib/view/pages/timetable/widgets/calendar/outside_chips.dart b/lib/view/pages/timetable/widgets/calendar/outside_chips.dart
index 7044b7d..a78cb59 100644
--- a/lib/view/pages/timetable/widgets/calendar/outside_chips.dart
+++ b/lib/view/pages/timetable/widgets/calendar/outside_chips.dart
@@ -78,39 +78,12 @@ class _OutsideDayColumn extends StatelessWidget {
   });
 
   void _showOverflow(BuildContext context, List<Appointment> hidden) {
-    showDetailsBottomSheet(
+    _showAppointmentOverflowSheet(
       context,
-      children: (sheetCtx) {
-        final tiles = <Widget>[];
-        for (var i = 0; i < hidden.length; i++) {
-          if (i > 0) tiles.add(const Divider(height: 1));
-          final apt = hidden[i];
-          tiles.add(
-            ListTile(
-              leading: Container(
-                width: 12,
-                height: 12,
-                decoration: BoxDecoration(
-                  color: apt.color,
-                  borderRadius: BorderRadius.circular(3),
-                ),
-              ),
-              title: Text(
-                apt.subject,
-                style: isCrossedOut(apt)
-                    ? const TextStyle(decoration: TextDecoration.lineThrough)
-                    : null,
-              ),
-              subtitle: Text(_subtitleFor(apt)),
-              onTap: () {
-                Navigator.of(sheetCtx).pop();
-                onAppointmentTap(apt);
-              },
-            ),
-          );
-        }
-        return tiles;
-      },
+      hidden,
+      onAppointmentTap: onAppointmentTap,
+      isCrossedOut: isCrossedOut,
+      subtitle: _subtitleFor,
     );
   }
 
diff --git a/lib/view/pages/timetable/widgets/calendar/week_grid.dart b/lib/view/pages/timetable/widgets/calendar/week_grid.dart
index def0ffc..6275dd9 100644
--- a/lib/view/pages/timetable/widgets/calendar/week_grid.dart
+++ b/lib/view/pages/timetable/widgets/calendar/week_grid.dart
@@ -252,39 +252,12 @@ class _DayColumn extends StatelessWidget {
   ) {
     final sorted = [...appointments]
       ..sort((a, b) => a.startTime.compareTo(b.startTime));
-    showDetailsBottomSheet(
+    _showAppointmentOverflowSheet(
       context,
-      children: (sheetContext) {
-        final tiles = <Widget>[];
-        for (var i = 0; i < sorted.length; i++) {
-          if (i > 0) tiles.add(const Divider(height: 1));
-          final apt = sorted[i];
-          tiles.add(
-            ListTile(
-              leading: Container(
-                width: 12,
-                height: 12,
-                decoration: BoxDecoration(
-                  color: apt.color,
-                  borderRadius: BorderRadius.circular(3),
-                ),
-              ),
-              title: Text(
-                apt.subject,
-                style: isCrossedOut(apt)
-                    ? const TextStyle(decoration: TextDecoration.lineThrough)
-                    : null,
-              ),
-              subtitle: Text(_overflowSubtitle(apt)),
-              onTap: () {
-                Navigator.of(sheetContext).pop();
-                onAppointmentTap(apt);
-              },
-            ),
-          );
-        }
-        return tiles;
-      },
+      sorted,
+      onAppointmentTap: onAppointmentTap,
+      isCrossedOut: isCrossedOut,
+      subtitle: _overflowSubtitle,
     );
   }
 
@@ -388,6 +361,52 @@ class _DayColumn extends StatelessWidget {
   }
 }
 
+/// Shared bottom sheet listing hidden appointments (used by both the in-grid
+/// and outside-hours overflow cells). [appointments] is rendered in the given
+/// order — callers pre-sort as needed.
+void _showAppointmentOverflowSheet(
+  BuildContext context,
+  List<Appointment> appointments, {
+  required void Function(Appointment) onAppointmentTap,
+  required bool Function(Appointment) isCrossedOut,
+  required String Function(Appointment) subtitle,
+}) {
+  showDetailsBottomSheet(
+    context,
+    children: (sheetContext) {
+      final tiles = <Widget>[];
+      for (var i = 0; i < appointments.length; i++) {
+        if (i > 0) tiles.add(const Divider(height: 1));
+        final apt = appointments[i];
+        tiles.add(
+          ListTile(
+            leading: Container(
+              width: 12,
+              height: 12,
+              decoration: BoxDecoration(
+                color: apt.color,
+                borderRadius: BorderRadius.circular(3),
+              ),
+            ),
+            title: Text(
+              apt.subject,
+              style: isCrossedOut(apt)
+                  ? const TextStyle(decoration: TextDecoration.lineThrough)
+                  : null,
+            ),
+            subtitle: Text(subtitle(apt)),
+            onTap: () {
+              Navigator.of(sheetContext).pop();
+              onAppointmentTap(apt);
+            },
+          ),
+        );
+      }
+      return tiles;
+    },
+  );
+}
+
 class _CurrentTimeMarker extends StatelessWidget {
   final DateTime now;
   final PeriodLayout layout;
diff --git a/lib/view/pages/timetable/widgets/timetable_calendar_view.dart b/lib/view/pages/timetable/widgets/timetable_calendar_view.dart
index 8b8f4db..6918cbb 100644
--- a/lib/view/pages/timetable/widgets/timetable_calendar_view.dart
+++ b/lib/view/pages/timetable/widgets/timetable_calendar_view.dart
@@ -57,9 +57,6 @@ class TimetableCalendarViewState extends State<TimetableCalendarView> {
     _calendarKey.currentState?.jumpToDate(_initialDisplayDate());
   }
 
-  bool isOnInitialWeek() =>
-      widget.state.startDate == _mondayOf(_initialDisplayDate());
-
   List<Appointment> _appointments(TimetableState state) {
     final timetableSettings = context
         .watch<SettingsCubit>()
diff --git a/lib/widget/async_actions/async_dialog_action.dart b/lib/widget/async_actions/async_dialog_action.dart
index 43f202d..50768ab 100644
--- a/lib/widget/async_actions/async_dialog_action.dart
+++ b/lib/widget/async_actions/async_dialog_action.dart
@@ -5,14 +5,12 @@ class AsyncDialogAction extends StatefulWidget {
   final AsyncActionCallback onConfirm;
   final String? cancelLabel;
   final AsyncErrorBuilder? errorBuilder;
-  final ButtonStyle? confirmStyle;
 
   const AsyncDialogAction({
     required this.confirmLabel,
     required this.onConfirm,
     this.cancelLabel = 'Abbrechen',
     this.errorBuilder,
-    this.confirmStyle,
     super.key,
   });
 
@@ -58,7 +56,6 @@ class _AsyncDialogActionState extends State<AsyncDialogAction> {
                   child: Text(widget.cancelLabel!),
                 ),
               TextButton(
-                style: widget.confirmStyle,
                 onPressed: _controller.busy
                     ? null
                     : () async {
diff --git a/lib/widget/avatar_actions_sheet.dart b/lib/widget/avatar_actions_sheet.dart
index 460a0f4..3a712de 100644
--- a/lib/widget/avatar_actions_sheet.dart
+++ b/lib/widget/avatar_actions_sheet.dart
@@ -4,6 +4,7 @@ import 'package:flutter/material.dart';
 import 'package:image_picker/image_picker.dart';
 
 import '../routing/app_routes.dart';
+import 'details_bottom_sheet.dart';
 import 'file_pick.dart';
 
 /// Result of the user's choice inside [showAvatarActionsSheet]. The sheet
@@ -32,69 +33,50 @@ Future<AvatarSheetResult?> showAvatarActionsSheet(
   required bool allowRemove,
 }) async {
   AvatarSheetResult? result;
-  await showModalBottomSheet<void>(
-    context: context,
-    isScrollControlled: true,
-    showDragHandle: true,
-    useSafeArea: true,
-    builder: (sheetContext) => SafeArea(
-      child: SingleChildScrollView(
-        padding: EdgeInsets.only(
-          bottom: 16 + MediaQuery.viewInsetsOf(sheetContext).bottom,
-        ),
-        child: Column(
-          mainAxisSize: MainAxisSize.min,
-          crossAxisAlignment: CrossAxisAlignment.stretch,
-          children: [
-            ListTile(
-              leading: const Icon(Icons.photo_library_outlined),
-              title: const Text('Aus Galerie wählen'),
-              onTap: () async {
-                final bytes = await _pickAndCrop(
-                  sheetContext,
-                  FilePick.singleGalleryPick,
-                );
-                if (bytes == null || !sheetContext.mounted) return;
-                result = AvatarUploadResult(bytes);
-                Navigator.of(sheetContext).pop();
-              },
-            ),
-            ListTile(
-              leading: const Icon(Icons.photo_camera_outlined),
-              title: const Text('Foto aufnehmen'),
-              onTap: () async {
-                final bytes = await _pickAndCrop(
-                  sheetContext,
-                  FilePick.cameraPick,
-                );
-                if (bytes == null || !sheetContext.mounted) return;
-                result = AvatarUploadResult(bytes);
-                Navigator.of(sheetContext).pop();
-              },
-            ),
-            if (allowRemove) ...[
-              const Divider(),
-              ListTile(
-                leading: Icon(
-                  Icons.delete_outline,
-                  color: Theme.of(sheetContext).colorScheme.error,
-                ),
-                title: Text(
-                  'Profilbild entfernen',
-                  style: TextStyle(
-                    color: Theme.of(sheetContext).colorScheme.error,
-                  ),
-                ),
-                onTap: () {
-                  result = const AvatarRemoveResult();
-                  Navigator.of(sheetContext).pop();
-                },
-              ),
-            ],
-          ],
-        ),
+  await showDetailsBottomSheet(
+    context,
+    children: (sheetContext) => [
+      ListTile(
+        leading: const Icon(Icons.photo_library_outlined),
+        title: const Text('Aus Galerie wählen'),
+        onTap: () async {
+          final bytes = await _pickAndCrop(
+            sheetContext,
+            FilePick.singleGalleryPick,
+          );
+          if (bytes == null || !sheetContext.mounted) return;
+          result = AvatarUploadResult(bytes);
+          Navigator.of(sheetContext).pop();
+        },
       ),
-    ),
+      ListTile(
+        leading: const Icon(Icons.photo_camera_outlined),
+        title: const Text('Foto aufnehmen'),
+        onTap: () async {
+          final bytes = await _pickAndCrop(sheetContext, FilePick.cameraPick);
+          if (bytes == null || !sheetContext.mounted) return;
+          result = AvatarUploadResult(bytes);
+          Navigator.of(sheetContext).pop();
+        },
+      ),
+      if (allowRemove) ...[
+        const Divider(),
+        ListTile(
+          leading: Icon(
+            Icons.delete_outline,
+            color: Theme.of(sheetContext).colorScheme.error,
+          ),
+          title: Text(
+            'Profilbild entfernen',
+            style: TextStyle(color: Theme.of(sheetContext).colorScheme.error),
+          ),
+          onTap: () {
+            result = const AvatarRemoveResult();
+            Navigator.of(sheetContext).pop();
+          },
+        ),
+      ],
+    ],
   );
   return result;
 }
diff --git a/lib/widget/chat_background_picker_sheet.dart b/lib/widget/chat_background_picker_sheet.dart
index 9d3a5d3..d0291d1 100644
--- a/lib/widget/chat_background_picker_sheet.dart
+++ b/lib/widget/chat_background_picker_sheet.dart
@@ -4,6 +4,7 @@ import 'package:flutter/material.dart';
 import 'package:image_picker/image_picker.dart';
 
 import '../routing/app_routes.dart';
+import 'details_bottom_sheet.dart';
 import 'file_pick.dart';
 
 /// Bottom sheet with "from gallery" and "take photo" actions for choosing a
@@ -13,44 +14,30 @@ import 'file_pick.dart';
 /// cancelled everything.
 Future<Uint8List?> showChatBackgroundPickerSheet(BuildContext context) async {
   Uint8List? result;
-  await showModalBottomSheet<void>(
-    context: context,
-    isScrollControlled: true,
-    showDragHandle: true,
-    useSafeArea: true,
-    builder: (sheetContext) => SafeArea(
-      child: SingleChildScrollView(
-        padding: EdgeInsets.only(
-          bottom: 16 + MediaQuery.viewInsetsOf(sheetContext).bottom,
-        ),
-        child: Column(
-          mainAxisSize: MainAxisSize.min,
-          crossAxisAlignment: CrossAxisAlignment.stretch,
-          children: [
-            ListTile(
-              leading: const Icon(Icons.photo_library_outlined),
-              title: const Text('Aus Galerie wählen'),
-              onTap: () async {
-                final bytes = await _pickRaw(FilePick.singleGalleryPick);
-                if (bytes == null || !sheetContext.mounted) return;
-                result = bytes;
-                Navigator.of(sheetContext).pop();
-              },
-            ),
-            ListTile(
-              leading: const Icon(Icons.photo_camera_outlined),
-              title: const Text('Foto aufnehmen'),
-              onTap: () async {
-                final bytes = await _pickRaw(FilePick.cameraPick);
-                if (bytes == null || !sheetContext.mounted) return;
-                result = bytes;
-                Navigator.of(sheetContext).pop();
-              },
-            ),
-          ],
-        ),
+  await showDetailsBottomSheet(
+    context,
+    children: (sheetContext) => [
+      ListTile(
+        leading: const Icon(Icons.photo_library_outlined),
+        title: const Text('Aus Galerie wählen'),
+        onTap: () async {
+          final bytes = await _pickRaw(FilePick.singleGalleryPick);
+          if (bytes == null || !sheetContext.mounted) return;
+          result = bytes;
+          Navigator.of(sheetContext).pop();
+        },
       ),
-    ),
+      ListTile(
+        leading: const Icon(Icons.photo_camera_outlined),
+        title: const Text('Foto aufnehmen'),
+        onTap: () async {
+          final bytes = await _pickRaw(FilePick.cameraPick);
+          if (bytes == null || !sheetContext.mounted) return;
+          result = bytes;
+          Navigator.of(sheetContext).pop();
+        },
+      ),
+    ],
   );
   return result;
 }
diff --git a/lib/widget/debug/cache_view.dart b/lib/widget/debug/cache_view.dart
index cbe095c..ff78296 100644
--- a/lib/widget/debug/cache_view.dart
+++ b/lib/widget/debug/cache_view.dart
@@ -33,7 +33,6 @@ class CacheView extends StatefulWidget {
 }
 
 class _CacheViewState extends State<CacheView> {
-  final Localstore storage = Localstore.instance;
   late Future<Map<String, dynamic>?> files;
 
   @override
diff --git a/lib/widget/debug/debug_tile.dart b/lib/widget/debug/debug_tile.dart
index f167d1c..389ff5f 100644
--- a/lib/widget/debug/debug_tile.dart
+++ b/lib/widget/debug/debug_tile.dart
@@ -15,8 +15,7 @@ class DebugTile {
       context.read<SettingsCubit>().val().devToolsEnabled &&
       (onlyInDebug ? kDebugMode : true);
 
-  Widget jsonData(Map<String, dynamic> data, {bool ignoreConfig = false}) =>
-      callback(
+  Widget jsonData(Map<String, dynamic> data) => callback(
         title: 'JSON daten anzeigen',
         onTab: () => JsonViewer.asDialog(context, data),
       );
diff --git a/lib/widget/debug/json_viewer.dart b/lib/widget/debug/json_viewer.dart
index 57e13a0..01f7cd4 100644
--- a/lib/widget/debug/json_viewer.dart
+++ b/lib/widget/debug/json_viewer.dart
@@ -4,21 +4,7 @@ import 'package:flutter/material.dart';
 
 import '../../utils/clipboard_helper.dart';
 
-class JsonViewer extends StatelessWidget {
-  final String title;
-  final Map<String, dynamic> data;
-
-  const JsonViewer({super.key, required this.title, required this.data});
-
-  @override
-  Widget build(BuildContext context) => Scaffold(
-    appBar: AppBar(title: Text(title)),
-    body: SingleChildScrollView(
-      scrollDirection: Axis.vertical,
-      child: Text(format(data)),
-    ),
-  );
-
+class JsonViewer {
   static final _encoder = const JsonEncoder.withIndent('  ');
 
   static String format(Map<String, dynamic> jsonInput) =>