fix(electron): sync title bar button colors with app theme

Update window control buttons (minimize, maximize, close) to match
the app's dark/light theme setting instead of always using white.

Fixes #5676

electron/electronAPI.d.ts

@@ -120,6 +120,8 @@ export interface ElectronAPI {
 
   sendSettingsUpdate(globalCfg: GlobalConfigState): void;
 
+  updateTitleBarDarkMode(isDarkMode: boolean): void;
+
   registerGlobalShortcuts(keyboardConfig: KeyboardConfig): void;
 
   showFullScreenBlocker(args: { msg?: string; takeABreakCfg: TakeABreakConfig }): void;

electron/main-window.ts

@@ -7,6 +7,7 @@ import {
   Menu,
   MenuItem,
   MenuItemConstructorOptions,
+  nativeTheme,
   shell,
 } from 'electron';
 import { errorHandlerWithFrontendInform } from './error-handler-with-frontend-inform';
@@ -85,11 +86,13 @@ export const createWindow = async ({
     persistedIsUseCustomWindowTitleBar ?? legacyIsUseObsidianStyleHeader ?? true;
   const titleBarStyle: BrowserWindowConstructorOptions['titleBarStyle'] =
     isUseCustomWindowTitleBar || IS_MAC ? 'hidden' : 'default';
+  // Determine initial symbol color based on system theme preference
+  const initialSymbolColor = nativeTheme.shouldUseDarkColors ? '#fff' : '#000';
   const titleBarOverlay: BrowserWindowConstructorOptions['titleBarOverlay'] =
     isUseCustomWindowTitleBar && !IS_MAC
       ? {
           color: '#00000000',
-          symbolColor: '#fff',
+          symbolColor: initialSymbolColor,
           height: 44,
         }
       : undefined;
@@ -221,6 +224,23 @@ export const createWindow = async ({
     mainWinModule.isAppReady = true;
   });
 
+  // Listen for theme changes to update title bar overlay symbol color
+  if (isUseCustomWindowTitleBar && !IS_MAC) {
+    ipcMain.on(IPC.UPDATE_TITLE_BAR_DARK_MODE, (ev, isDarkMode: boolean) => {
+      try {
+        const symbolColor = isDarkMode ? '#fff' : '#000';
+        mainWin.setTitleBarOverlay({
+          color: '#00000000',
+          symbolColor,
+          height: 44,
+        });
+      } catch (e) {
+        // setTitleBarOverlay may not be available on all platforms
+        log('Failed to update title bar overlay:', e);
+      }
+    });
+  }
+
   return mainWin;
 };
 

electron/preload.ts

@@ -99,6 +99,8 @@ const ea: ElectronAPI = {
   sendAppSettingsToElectron: (globalCfg) =>
     _send('TRANSFER_SETTINGS_TO_ELECTRON', globalCfg),
   sendSettingsUpdate: (globalCfg) => _send('UPDATE_SETTINGS', globalCfg),
+  updateTitleBarDarkMode: (isDarkMode: boolean) =>
+    _send('UPDATE_TITLE_BAR_DARK_MODE', isDarkMode),
   registerGlobalShortcuts: (keyboardCfg) =>
     _send('REGISTER_GLOBAL_SHORTCUTS', keyboardCfg),
   showFullScreenBlocker: (args) => _send('FULL_SCREEN_BLOCKER', args),

electron/shared-with-frontend/ipc-events.const.ts

@@ -69,6 +69,7 @@ export enum IPC {
   PLUGIN_EXEC_NODE_SCRIPT = 'PLUGIN_EXEC_NODE_SCRIPT',
 
   UPDATE_SETTINGS = 'UPDATE_SETTINGS',
+  UPDATE_TITLE_BAR_DARK_MODE = 'UPDATE_TITLE_BAR_DARK_MODE',
 
   // maybe_UPDATE_CURRENT_TASK = 'UPDATE_CURRENT_TASK',
   // maybe_IS_IDLE = 'IS_IDLE',

src/app/core/theme/global-theme.service.ts

@@ -5,6 +5,7 @@ import {
   Injectable,
   runInInjectionContext,
   signal,
+  untracked,
 } from '@angular/core';
 import { toObservable, toSignal } from '@angular/core/rxjs-interop';
 import { BodyClass, IS_ELECTRON } from '../../app.constants';
@@ -231,6 +232,19 @@ export class GlobalThemeService {
       this._setColorTheme(theme),
     );
     this._isDarkThemeObs$.subscribe((isDarkTheme) => this._setDarkTheme(isDarkTheme));
+
+    // Update Electron title bar overlay when dark mode changes
+    if (IS_ELECTRON && !IS_MAC) {
+      effect(() => {
+        const isDark = this.isDarkTheme();
+        // Use untracked to prevent reading misc from creating a dependency
+        const misc = untracked(() => this._globalConfigService.misc());
+        // Only update if custom window title bar is enabled
+        if (misc?.isUseCustomWindowTitleBar !== false) {
+          window.ea.updateTitleBarDarkMode(isDark);
+        }
+      });
+    }
   }
 
   private _initHandlersForInitialBodyClasses(): void {