diff --git a/desktop/src/__tests__/generalSettings.test.tsx b/desktop/src/__tests__/generalSettings.test.tsx
index 604a1a37..cf9cecfe 100644
--- a/desktop/src/__tests__/generalSettings.test.tsx
+++ b/desktop/src/__tests__/generalSettings.test.tsx
@@ -144,6 +144,7 @@ describe('Settings > General tab', () => {
       skipWebFetchPreflight: true,
       desktopNotificationsEnabled: true,
       responseLanguage: '',
+      uiZoom: 1,
       webSearch: { mode: 'auto', tavilyApiKey: '', braveApiKey: '' },
       h5Access: {
         enabled: false,
@@ -167,6 +168,9 @@ describe('Settings > General tab', () => {
       setResponseLanguage: vi.fn().mockImplementation(async (language: string) => {
         useSettingsStore.setState({ responseLanguage: language })
       }),
+      setUiZoom: vi.fn().mockImplementation((uiZoom: number) => {
+        useSettingsStore.setState({ uiZoom })
+      }),
       setWebSearch: vi.fn().mockImplementation(async (webSearch) => {
         useSettingsStore.setState({ webSearch })
       }),
@@ -251,6 +255,26 @@ describe('Settings > General tab', () => {
     expect(screen.getByRole('button', { name: 'Warm Classic' })).toHaveAttribute('aria-pressed', 'false')
   })
 
+  it('updates the shared UI zoom setting from the General display control', async () => {
+    render(<Settings />)
+
+    fireEvent.click(screen.getByText('General'))
+    await act(async () => {
+      fireEvent.change(screen.getByLabelText('UI Zoom'), {
+        target: { value: '1.25', valueAsNumber: 1.25 },
+      })
+    })
+
+    expect(useSettingsStore.getState().setUiZoom).toHaveBeenCalledWith(1.25)
+    expect(screen.getByText('125%')).toBeInTheDocument()
+
+    await act(async () => {
+      fireEvent.click(screen.getByRole('button', { name: 'Reset UI zoom to 100%' }))
+    })
+
+    expect(useSettingsStore.getState().setUiZoom).toHaveBeenLastCalledWith(1)
+  })
+
   it('opens the Token usage tab from Settings navigation above Diagnostics', () => {
     render(<Settings />)
 
diff --git a/desktop/src/components/layout/AppShell.tsx b/desktop/src/components/layout/AppShell.tsx
index af09547b..c9e578ab 100644
--- a/desktop/src/components/layout/AppShell.tsx
+++ b/desktop/src/components/layout/AppShell.tsx
@@ -28,7 +28,6 @@ function isChatTab(tab: Tab | undefined) {
 
 export function AppShell() {
   const fetchSettings = useSettingsStore((s) => s.fetchAll)
-  const uiZoom = useSettingsStore((s) => s.uiZoom)
   const sidebarOpen = useUIStore((s) => s.sidebarOpen)
   const toggleSidebar = useUIStore((s) => s.toggleSidebar)
   const setSidebarOpen = useUIStore((s) => s.setSidebarOpen)
@@ -195,7 +194,7 @@ export function AppShell() {
   }
 
   return (
-    <div className={`app-shell app-shell-viewport flex overflow-hidden bg-[var(--color-surface)]${isMobileShell ? ' app-shell--mobile' : ''}`} style={{ zoom: uiZoom }}>
+    <div className={`app-shell app-shell-viewport flex overflow-hidden bg-[var(--color-surface)]${isMobileShell ? ' app-shell--mobile' : ''}`}>
       {isMobileShell && effectiveSidebarOpen ? (
         <button
           type="button"
diff --git a/desktop/src/hooks/useKeyboardShortcuts.test.tsx b/desktop/src/hooks/useKeyboardShortcuts.test.tsx
index 807d2b9c..531d9652 100644
--- a/desktop/src/hooks/useKeyboardShortcuts.test.tsx
+++ b/desktop/src/hooks/useKeyboardShortcuts.test.tsx
@@ -1,6 +1,7 @@
 import { afterEach, beforeEach, describe, expect, it } from 'vitest'
 import { cleanup, fireEvent, render, waitFor } from '@testing-library/react'
 import { APP_ZOOM_STORAGE_KEY } from '../lib/appZoom'
+import { useSettingsStore } from '../stores/settingsStore'
 import { useKeyboardShortcuts } from './useKeyboardShortcuts'
 
 function ShortcutHost() {
@@ -22,6 +23,7 @@ describe('useKeyboardShortcuts app zoom', () => {
     document.documentElement.removeAttribute('data-app-zoom-percent')
     document.documentElement.style.removeProperty('--app-zoom')
     document.body.style.removeProperty('zoom')
+    useSettingsStore.setState({ uiZoom: 1 })
     setNavigatorPlatform('Win32')
   })
 
@@ -41,6 +43,7 @@ describe('useKeyboardShortcuts app zoom', () => {
     await waitFor(() => {
       expect(window.localStorage.getItem(APP_ZOOM_STORAGE_KEY)).toBe('1.1')
     })
+    expect(useSettingsStore.getState().uiZoom).toBe(1.1)
     expect(document.documentElement.getAttribute('data-app-zoom-percent')).toBe('110')
 
     fireEvent.keyDown(document, {
@@ -52,6 +55,7 @@ describe('useKeyboardShortcuts app zoom', () => {
     await waitFor(() => {
       expect(window.localStorage.getItem(APP_ZOOM_STORAGE_KEY)).toBe('1')
     })
+    expect(useSettingsStore.getState().uiZoom).toBe(1)
 
     fireEvent.keyDown(document, {
       code: 'NumpadAdd',
diff --git a/desktop/src/hooks/useKeyboardShortcuts.ts b/desktop/src/hooks/useKeyboardShortcuts.ts
index c58d2705..282dc99e 100644
--- a/desktop/src/hooks/useKeyboardShortcuts.ts
+++ b/desktop/src/hooks/useKeyboardShortcuts.ts
@@ -4,12 +4,10 @@ import { useChatStore } from '../stores/chatStore'
 import { useTabStore } from '../stores/tabStore'
 import { useUIStore } from '../stores/uiStore'
 import {
-  applyAppZoomLevel,
   getAppZoomKeyboardAction,
-  initializeAppZoom,
   nextAppZoomLevel,
-  readStoredAppZoomLevel,
 } from '../lib/appZoom'
+import { useSettingsStore } from '../stores/settingsStore'
 
 export function useKeyboardShortcuts() {
   const setActiveSession = useSessionStore((s) => s.setActiveSession)
@@ -20,6 +18,8 @@ export function useKeyboardShortcuts() {
   const stopGeneration = useChatStore((s) => s.stopGeneration)
   const activeTabId = useTabStore((s) => s.activeTabId)
   const chatState = useChatStore((s) => activeTabId ? s.sessions[activeTabId]?.chatState ?? 'idle' : 'idle')
+  const uiZoom = useSettingsStore((s) => s.uiZoom)
+  const setUiZoom = useSettingsStore((s) => s.setUiZoom)
 
   const activeModalRef = useRef(activeModal)
   activeModalRef.current = activeModal
@@ -27,18 +27,17 @@ export function useKeyboardShortcuts() {
   chatStateRef.current = chatState
   const activeTabIdRef = useRef(activeTabId)
   activeTabIdRef.current = activeTabId
-  const appZoomLevelRef = useRef(readStoredAppZoomLevel())
+  const appZoomLevelRef = useRef(uiZoom)
+  appZoomLevelRef.current = uiZoom
 
   useEffect(() => {
-    void initializeAppZoom()
-
     const handler = (e: KeyboardEvent) => {
       const zoomAction = getAppZoomKeyboardAction(e)
       if (zoomAction) {
         e.preventDefault()
         const nextZoom = nextAppZoomLevel(appZoomLevelRef.current, zoomAction)
         appZoomLevelRef.current = nextZoom
-        void applyAppZoomLevel(nextZoom)
+        setUiZoom(nextZoom)
         return
       }
 
@@ -80,5 +79,5 @@ export function useKeyboardShortcuts() {
 
     document.addEventListener('keydown', handler)
     return () => document.removeEventListener('keydown', handler)
-  }, [closeModal, setActiveSession, setActiveView, setSidebarOpen, stopGeneration])
+  }, [closeModal, setActiveSession, setActiveView, setSidebarOpen, setUiZoom, stopGeneration])
 }
diff --git a/desktop/src/i18n/locales/en.ts b/desktop/src/i18n/locales/en.ts
index 75352497..5e3a70a2 100644
--- a/desktop/src/i18n/locales/en.ts
+++ b/desktop/src/i18n/locales/en.ts
@@ -768,7 +768,8 @@ export const en = {
   'settings.general.webSearchHint': 'Auto uses native Claude web search for Claude model names, then falls back to Tavily and Brave keys.',
   'settings.general.webSearchSave': 'Save',
   'settings.general.uiZoom': 'UI Zoom',
-  'settings.general.uiZoomDescription': 'Scale the entire interface for better visibility on high-DPI displays.',
+  'settings.general.uiZoomDescription': 'Adjust the size of the entire interface.',
+  'settings.general.uiZoomReset': 'Reset UI zoom to 100%',
 
   // ─── Empty Session ──────────────────────────────────────
   'empty.title': 'New session',
diff --git a/desktop/src/i18n/locales/zh.ts b/desktop/src/i18n/locales/zh.ts
index 3cde0ada..9a2fba59 100644
--- a/desktop/src/i18n/locales/zh.ts
+++ b/desktop/src/i18n/locales/zh.ts
@@ -770,7 +770,8 @@ export const zh: Record<TranslationKey, string> = {
   'settings.general.webSearchHint': '自动模式会对 Claude 模型名优先使用原生 WebSearch，失败或非 Claude 模型时再使用 Tavily/Brave。',
   'settings.general.webSearchSave': '保存',
   'settings.general.uiZoom': '界面缩放',
-  'settings.general.uiZoomDescription': '缩放整个界面，以便在高 DPI 屏幕上获得更好的可见性。',
+  'settings.general.uiZoomDescription': '调整整个界面的显示大小。',
+  'settings.general.uiZoomReset': '重置界面缩放到 100%',
 
   // ─── Empty Session ──────────────────────────────────────
   'empty.title': '新建会话',
diff --git a/desktop/src/lib/appZoom.test.ts b/desktop/src/lib/appZoom.test.ts
index b641183d..7e5196fc 100644
--- a/desktop/src/lib/appZoom.test.ts
+++ b/desktop/src/lib/appZoom.test.ts
@@ -1,6 +1,7 @@
 import { beforeEach, describe, expect, it } from 'vitest'
 import {
   APP_ZOOM_STORAGE_KEY,
+  LEGACY_UI_ZOOM_STORAGE_KEY,
   applyAppZoomLevel,
   getAppZoomKeyboardAction,
   initializeAppZoom,
@@ -39,6 +40,15 @@ describe('appZoom', () => {
     expect(window.localStorage.getItem(APP_ZOOM_STORAGE_KEY)).toBe('1.2')
   })
 
+  it('reads the legacy UI zoom key when the app zoom key is absent', async () => {
+    window.localStorage.setItem(LEGACY_UI_ZOOM_STORAGE_KEY, '1.25')
+
+    await initializeAppZoom()
+
+    expect(document.documentElement.getAttribute('data-app-zoom-percent')).toBe('125')
+    expect(window.localStorage.getItem(APP_ZOOM_STORAGE_KEY)).toBeNull()
+  })
+
   it('persists app zoom changes', async () => {
     await applyAppZoomLevel(1.3)
 
diff --git a/desktop/src/lib/appZoom.ts b/desktop/src/lib/appZoom.ts
index b8ac9d02..3127d42c 100644
--- a/desktop/src/lib/appZoom.ts
+++ b/desktop/src/lib/appZoom.ts
@@ -1,8 +1,10 @@
 export const APP_ZOOM_STORAGE_KEY = 'cc-haha-app-zoom'
+export const LEGACY_UI_ZOOM_STORAGE_KEY = 'cc-haha-ui-zoom'
 export const DEFAULT_APP_ZOOM = 1
 export const MIN_APP_ZOOM = 0.5
 export const MAX_APP_ZOOM = 2
 export const APP_ZOOM_STEP = 0.1
+export const APP_ZOOM_CONTROL_STEP = 0.05
 
 export type AppZoomAction = 'in' | 'out' | 'reset'
 
@@ -45,7 +47,9 @@ export function isValidStoredAppZoomLevel(value: string | null): boolean {
 export function readStoredAppZoomLevel(storage: StorageLike | null = getDefaultStorage()): number {
   if (!storage) return DEFAULT_APP_ZOOM
   try {
-    return normalizeAppZoomLevel(storage.getItem(APP_ZOOM_STORAGE_KEY))
+    const stored = storage.getItem(APP_ZOOM_STORAGE_KEY)
+    if (stored !== null) return normalizeAppZoomLevel(stored)
+    return normalizeAppZoomLevel(storage.getItem(LEGACY_UI_ZOOM_STORAGE_KEY))
   } catch {
     return DEFAULT_APP_ZOOM
   }
diff --git a/desktop/src/lib/doctorRepair.ts b/desktop/src/lib/doctorRepair.ts
index 55b47907..e287d624 100644
--- a/desktop/src/lib/doctorRepair.ts
+++ b/desktop/src/lib/doctorRepair.ts
@@ -1,5 +1,5 @@
 import { doctorApi, type DoctorReportRepairResponse } from '../api/doctor'
-import { APP_ZOOM_STORAGE_KEY } from './appZoom'
+import { APP_ZOOM_STORAGE_KEY, LEGACY_UI_ZOOM_STORAGE_KEY } from './appZoom'
 import { DESKTOP_PERSISTENCE_VERSION_KEY } from './persistenceMigrations'
 
 export const SAFE_DOCTOR_STORAGE_KEYS = [
@@ -8,6 +8,7 @@ export const SAFE_DOCTOR_STORAGE_KEYS = [
   'cc-haha-theme',
   'cc-haha-locale',
   APP_ZOOM_STORAGE_KEY,
+  LEGACY_UI_ZOOM_STORAGE_KEY,
   DESKTOP_PERSISTENCE_VERSION_KEY,
 ] as const
 
diff --git a/desktop/src/lib/persistenceMigrations.test.ts b/desktop/src/lib/persistenceMigrations.test.ts
index 397f8bc6..de466cb0 100644
--- a/desktop/src/lib/persistenceMigrations.test.ts
+++ b/desktop/src/lib/persistenceMigrations.test.ts
@@ -81,6 +81,19 @@ describe('desktop persistence migrations', () => {
     expect(window.localStorage.getItem('cc-haha-app-zoom')).toBeNull()
   })
 
+  test('migrates the legacy UI zoom key into app zoom storage', () => {
+    window.localStorage.setItem('cc-haha-ui-zoom', '1.25')
+
+    const report = runDesktopPersistenceMigrations()
+
+    expect(report.migratedKeys).toEqual(expect.arrayContaining([
+      'cc-haha-app-zoom',
+      'cc-haha-ui-zoom',
+    ]))
+    expect(window.localStorage.getItem('cc-haha-app-zoom')).toBe('1.25')
+    expect(window.localStorage.getItem('cc-haha-ui-zoom')).toBeNull()
+  })
+
   test('does not throw if schema version persistence is blocked', () => {
     const storage = {
       getItem: window.localStorage.getItem.bind(window.localStorage),
diff --git a/desktop/src/lib/persistenceMigrations.ts b/desktop/src/lib/persistenceMigrations.ts
index f10a77b9..b6255cdc 100644
--- a/desktop/src/lib/persistenceMigrations.ts
+++ b/desktop/src/lib/persistenceMigrations.ts
@@ -1,5 +1,10 @@
 import { THEME_MODES } from '../types/settings'
-import { APP_ZOOM_STORAGE_KEY, isValidStoredAppZoomLevel } from './appZoom'
+import {
+  APP_ZOOM_STORAGE_KEY,
+  LEGACY_UI_ZOOM_STORAGE_KEY,
+  isValidStoredAppZoomLevel,
+  normalizeAppZoomLevel,
+} from './appZoom'
 
 export const CURRENT_DESKTOP_PERSISTENCE_SCHEMA_VERSION = 1
 export const DESKTOP_PERSISTENCE_VERSION_KEY = 'cc-haha.persistence.schemaVersion'
@@ -121,6 +126,17 @@ function normalizeAppZoomKey(storage: StorageLike, report: DesktopMigrationRepor
     storage.removeItem(APP_ZOOM_STORAGE_KEY)
     report.migratedKeys.push(APP_ZOOM_STORAGE_KEY)
   }
+
+  const currentValue = storage.getItem(APP_ZOOM_STORAGE_KEY)
+  const legacyValue = storage.getItem(LEGACY_UI_ZOOM_STORAGE_KEY)
+  if (currentValue === null && legacyValue !== null && isValidStoredAppZoomLevel(legacyValue)) {
+    storage.setItem(APP_ZOOM_STORAGE_KEY, String(normalizeAppZoomLevel(legacyValue)))
+    report.migratedKeys.push(APP_ZOOM_STORAGE_KEY)
+  }
+  if (legacyValue !== null) {
+    storage.removeItem(LEGACY_UI_ZOOM_STORAGE_KEY)
+    report.migratedKeys.push(LEGACY_UI_ZOOM_STORAGE_KEY)
+  }
 }
 
 function runMigrationStep(
diff --git a/desktop/src/main.tsx b/desktop/src/main.tsx
index b239923f..c6a55b7c 100644
--- a/desktop/src/main.tsx
+++ b/desktop/src/main.tsx
@@ -1,9 +1,11 @@
 import React from 'react'
 import ReactDOM from 'react-dom/client'
 import './theme/globals.css'
+import { initializeAppZoom } from './lib/appZoom'
 import { runDesktopPersistenceMigrations } from './lib/persistenceMigrations'
 
 runDesktopPersistenceMigrations()
+void initializeAppZoom()
 const [{ App }, { ErrorBoundary }, { installClientDiagnosticsCapture }, { initializeTheme }] = await Promise.all([
   import('./App'),
   import('./components/ErrorBoundary'),
diff --git a/desktop/src/pages/Settings.tsx b/desktop/src/pages/Settings.tsx
index 4e7cacaa..47d84e8d 100644
--- a/desktop/src/pages/Settings.tsx
+++ b/desktop/src/pages/Settings.tsx
@@ -1,7 +1,7 @@
 import { useState, useEffect, useMemo, useRef, type ReactNode } from 'react'
 import QRCode from 'qrcode'
 import { Copy, Eye, EyeOff, PowerOff, QrCode, RotateCw } from 'lucide-react'
-import { useSettingsStore, UI_ZOOM_MIN, UI_ZOOM_MAX, UI_ZOOM_STEP } from '../stores/settingsStore'
+import { useSettingsStore, UI_ZOOM_DEFAULT, UI_ZOOM_MIN, UI_ZOOM_MAX, UI_ZOOM_STEP } from '../stores/settingsStore'
 import { useProviderStore } from '../stores/providerStore'
 import { useTranslation } from '../i18n'
 import { Modal } from '../components/shared/Modal'
@@ -1532,6 +1532,45 @@ function GeneralSettings() {
         ))}
       </div>
 
+      {/* UI Zoom */}
+      <div className="mb-8">
+        <div className="mb-3 flex items-end justify-between gap-3">
+          <div className="min-w-0">
+            <h2 className="text-base font-semibold text-[var(--color-text-primary)] mb-1">{t('settings.general.uiZoom')}</h2>
+            <p className="text-sm text-[var(--color-text-tertiary)]">{t('settings.general.uiZoomDescription')}</p>
+          </div>
+          <div className="flex flex-shrink-0 items-center gap-2">
+            <span className="min-w-[48px] rounded-md bg-[var(--color-surface-container-low)] px-2 py-1 text-center text-sm font-medium text-[var(--color-text-secondary)]">
+              {Math.round(uiZoom * 100)}%
+            </span>
+            <button
+              type="button"
+              aria-label={t('settings.general.uiZoomReset')}
+              title={t('settings.general.uiZoomReset')}
+              onClick={() => setUiZoom(UI_ZOOM_DEFAULT)}
+              className="inline-flex h-8 items-center gap-1.5 rounded-md border border-[var(--color-border)] px-2 text-xs font-medium text-[var(--color-text-secondary)] transition-colors hover:border-[var(--color-border-focus)] hover:bg-[var(--color-surface-hover)] focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-[var(--color-border-focus)]"
+            >
+              <RotateCw className="h-3.5 w-3.5" aria-hidden="true" />
+              100%
+            </button>
+          </div>
+        </div>
+        <div className="flex items-center gap-3">
+          <span className="w-9 text-right text-xs text-[var(--color-text-tertiary)]">{Math.round(UI_ZOOM_MIN * 100)}%</span>
+          <input
+            type="range"
+            aria-label={t('settings.general.uiZoom')}
+            min={UI_ZOOM_MIN}
+            max={UI_ZOOM_MAX}
+            step={UI_ZOOM_STEP}
+            value={uiZoom}
+            onChange={(e) => setUiZoom(e.currentTarget.valueAsNumber)}
+            className="flex-1"
+          />
+          <span className="w-9 text-xs text-[var(--color-text-tertiary)]">{Math.round(UI_ZOOM_MAX * 100)}%</span>
+        </div>
+      </div>
+
       {/* Language selector */}
       <h2 className="text-base font-semibold text-[var(--color-text-primary)] mb-1">{t('settings.general.languageTitle')}</h2>
       <p className="text-sm text-[var(--color-text-tertiary)] mb-3">{t('settings.general.languageDescription')}</p>
@@ -1777,33 +1816,6 @@ function GeneralSettings() {
           </div>
         </div>
       </div>
-      {/* UI Zoom */}
-      <div className="mt-8">
-        <h2 className="text-base font-semibold text-[var(--color-text-primary)] mb-1">{t('settings.general.uiZoom')}</h2>
-        <p className="text-sm text-[var(--color-text-tertiary)] mb-3">{t('settings.general.uiZoomDescription')}</p>
-        <div className="flex flex-col gap-2">
-          <div className="flex items-center justify-end">
-            <span className="text-sm text-[var(--color-text-secondary)]">
-              {Math.round(uiZoom * 100)}%
-            </span>
-          </div>
-          <div className="flex items-center gap-3">
-            <span className="text-xs text-[var(--color-text-tertiary)]">{Math.round(UI_ZOOM_MIN * 100)}%</span>
-            <input
-              type="range"
-              min={UI_ZOOM_MIN}
-              max={UI_ZOOM_MAX}
-              step={UI_ZOOM_STEP}
-              value={uiZoom}
-              onChange={(e) => setUiZoom(parseFloat(e.target.value))}
-              onMouseUp={(e) => e.currentTarget.blur()}
-              className="flex-1"
-            />
-            <span className="text-xs text-[var(--color-text-tertiary)]">{Math.round(UI_ZOOM_MAX * 100)}%</span>
-          </div>
-        </div>
-      </div>
-
     </div>
   )
 }
diff --git a/desktop/src/stores/settingsStore.test.ts b/desktop/src/stores/settingsStore.test.ts
index 77e7d8d4..f632dc79 100644
--- a/desktop/src/stores/settingsStore.test.ts
+++ b/desktop/src/stores/settingsStore.test.ts
@@ -22,6 +22,47 @@ describe('settingsStore locale defaults', () => {
   })
 })
 
+describe('settingsStore UI zoom', () => {
+  beforeEach(() => {
+    vi.resetModules()
+    window.localStorage.clear()
+    document.documentElement.removeAttribute('data-app-zoom-percent')
+    document.documentElement.style.removeProperty('--app-zoom')
+    document.body.style.removeProperty('zoom')
+  })
+
+  it('hydrates from the app zoom storage key', async () => {
+    window.localStorage.setItem('cc-haha-app-zoom', '1.25')
+
+    const { useSettingsStore } = await import('./settingsStore')
+
+    expect(useSettingsStore.getState().uiZoom).toBe(1.25)
+  })
+
+  it('applies and persists UI zoom changes through the shared app zoom controller', async () => {
+    const { useSettingsStore } = await import('./settingsStore')
+
+    useSettingsStore.getState().setUiZoom(1.25)
+
+    await vi.waitFor(() => {
+      expect(window.localStorage.getItem('cc-haha-app-zoom')).toBe('1.25')
+    })
+    expect(useSettingsStore.getState().uiZoom).toBe(1.25)
+    expect(document.documentElement.getAttribute('data-app-zoom-percent')).toBe('125')
+  })
+
+  it('clamps UI zoom changes to the supported range', async () => {
+    const { useSettingsStore } = await import('./settingsStore')
+
+    useSettingsStore.getState().setUiZoom(9)
+
+    await vi.waitFor(() => {
+      expect(window.localStorage.getItem('cc-haha-app-zoom')).toBe('2')
+    })
+    expect(useSettingsStore.getState().uiZoom).toBe(2)
+  })
+})
+
 describe('settingsStore desktop notification persistence', () => {
   beforeEach(() => {
     vi.resetModules()
diff --git a/desktop/src/stores/settingsStore.ts b/desktop/src/stores/settingsStore.ts
index 81b7e9ee..088319cb 100644
--- a/desktop/src/stores/settingsStore.ts
+++ b/desktop/src/stores/settingsStore.ts
@@ -5,13 +5,22 @@ import { modelsApi } from '../api/models'
 import { h5AccessApi } from '../api/h5Access'
 import { isThemeMode, type H5AccessSettings, type PermissionMode, type EffortLevel, type ModelInfo, type ThemeMode, type WebSearchSettings } from '../types/settings'
 import type { Locale } from '../i18n'
+import {
+  APP_ZOOM_CONTROL_STEP,
+  DEFAULT_APP_ZOOM,
+  MAX_APP_ZOOM,
+  MIN_APP_ZOOM,
+  applyAppZoomLevel,
+  normalizeAppZoomLevel,
+  readStoredAppZoomLevel,
+} from '../lib/appZoom'
 import { useUIStore } from './uiStore'
 
 const LOCALE_STORAGE_KEY = 'cc-haha-locale'
-const UI_ZOOM_STORAGE_KEY = 'cc-haha-ui-zoom'
-export const UI_ZOOM_MIN = 0.5
-export const UI_ZOOM_MAX = 2.0
-export const UI_ZOOM_STEP = 0.05
+export const UI_ZOOM_MIN = MIN_APP_ZOOM
+export const UI_ZOOM_MAX = MAX_APP_ZOOM
+export const UI_ZOOM_STEP = APP_ZOOM_CONTROL_STEP
+export const UI_ZOOM_DEFAULT = DEFAULT_APP_ZOOM
 let desktopNotificationsSaveQueue: Promise<void> = Promise.resolve()
 
 function getStoredLocale(): Locale {
@@ -22,17 +31,6 @@ function getStoredLocale(): Locale {
   return 'zh'
 }
 
-function getStoredUiZoom(): number {
-  try {
-    const stored = localStorage.getItem(UI_ZOOM_STORAGE_KEY)
-    if (stored === null) return 1.0
-    const parsed = parseFloat(stored)
-    if (isNaN(parsed)) return 1.0
-    return Math.min(UI_ZOOM_MAX, Math.max(UI_ZOOM_MIN, parsed))
-  } catch { /* localStorage unavailable */ }
-  return 1.0
-}
-
 type SettingsStore = {
   permissionMode: PermissionMode
   currentModel: ModelInfo | null
@@ -96,14 +94,14 @@ export const useSettingsStore = create<SettingsStore>((set, get) => ({
   h5Access: DEFAULT_H5_ACCESS_SETTINGS,
   h5AccessError: null,
   responseLanguage: '',
-  uiZoom: getStoredUiZoom(),
+  uiZoom: readStoredAppZoomLevel(),
   isLoading: false,
   error: null,
 
   setUiZoom: (zoom: number) => {
-    const clamped = Math.min(UI_ZOOM_MAX, Math.max(UI_ZOOM_MIN, zoom))
-    set({ uiZoom: clamped })
-    try { localStorage.setItem(UI_ZOOM_STORAGE_KEY, String(clamped)) } catch { /* noop */ }
+    const level = normalizeAppZoomLevel(zoom)
+    set({ uiZoom: level })
+    void applyAppZoomLevel(level)
   },
 
   fetchAll: async () => {
diff --git a/desktop/src/types/settings.ts b/desktop/src/types/settings.ts
index 7a2e5393..4a5b247a 100644
--- a/desktop/src/types/settings.ts
+++ b/desktop/src/types/settings.ts
@@ -43,6 +43,5 @@ export type UserSettings = {
   desktopNotificationsEnabled?: boolean
   webSearch?: WebSearchSettings
   language?: string
-  uiZoom?: number
   [key: string]: unknown
 }