diff --git a/apps/web/src/components/ui/photo-viewer/animations/usePhotoViewerTransitions.ts b/apps/web/src/components/ui/photo-viewer/animations/usePhotoViewerTransitions.ts
index 81101fdd..4ebeebf4 100644
--- a/apps/web/src/components/ui/photo-viewer/animations/usePhotoViewerTransitions.ts
+++ b/apps/web/src/components/ui/photo-viewer/animations/usePhotoViewerTransitions.ts
@@ -118,11 +118,6 @@ export const usePhotoViewerTransitions = ({
     if (!isOpen || !currentPhoto) return
     if (entryTransition || isViewerContentVisible) return
 
-    if (typeof window === 'undefined') {
-      setIsViewerContentVisible(true)
-      return
-    }
-
     const triggerEl = resolveTriggerElement()
 
     if (!triggerEl) {
@@ -208,12 +203,6 @@ export const usePhotoViewerTransitions = ({
       return
     }
 
-    if (typeof window === 'undefined') {
-      wasOpenRef.current = false
-      restoreTriggerElementVisibility()
-      return
-    }
-
     const triggerEl = resolveTriggerElement()
 
     if (!triggerEl || !triggerEl.isConnected) {
diff --git a/apps/web/src/components/ui/photo-viewer/animations/utils.ts b/apps/web/src/components/ui/photo-viewer/animations/utils.ts
index 388c5719..858ba8ba 100644
--- a/apps/web/src/components/ui/photo-viewer/animations/utils.ts
+++ b/apps/web/src/components/ui/photo-viewer/animations/utils.ts
@@ -15,7 +15,7 @@ const THUMBNAIL_PADDING = {
 } as const
 
 export const escapeAttributeValue = (value: string) => {
-  if (typeof window !== 'undefined' && window.CSS?.escape) {
+  if (window.CSS?.escape) {
     return window.CSS.escape(value)
   }
 
@@ -23,14 +23,13 @@ export const escapeAttributeValue = (value: string) => {
 }
 
 const getRootFontSize = () => {
-  if (typeof window === 'undefined') return 16
   const value = window.getComputedStyle(document.documentElement).fontSize
   const parsed = Number.parseFloat(value || '16')
   return Number.isNaN(parsed) ? 16 : parsed
 }
 
 export const getBorderRadius = (element: Element | null) => {
-  if (typeof window === 'undefined' || !element) return 0
+  if (!element) return 0
 
   const computedStyle = window.getComputedStyle(element)
   const radiusCandidates = [
diff --git a/apps/web/src/config/index.ts b/apps/web/src/config/index.ts
index ebfd3beb..e19d2bf1 100644
--- a/apps/web/src/config/index.ts
+++ b/apps/web/src/config/index.ts
@@ -11,7 +11,7 @@ const defaultInjectConfig = {
 export const injectConfig = merge(defaultInjectConfig, __CONFIG__)
 
 const getInjectedSiteConfig = (): Partial<SiteConfig> | undefined => {
-  if (typeof window !== 'undefined' && window.__SITE_CONFIG__) {
+  if (window.__SITE_CONFIG__) {
     return window.__SITE_CONFIG__
   }
 
diff --git a/apps/web/src/lib/device-viewport.ts b/apps/web/src/lib/device-viewport.ts
index 40a852d6..36977692 100644
--- a/apps/web/src/lib/device-viewport.ts
+++ b/apps/web/src/lib/device-viewport.ts
@@ -1,7 +1,6 @@
 export const isSafari = /Safari/.test(navigator.userAgent) && !/Chrome/.test(navigator.userAgent)
 
 export const isMobileDevice = (() => {
-  if (typeof window === 'undefined') return false
   return (
     /Android|webOS|iPhone|iPad|iPod|BlackBerry|IEMobile|Opera Mini/i.test(navigator.userAgent) ||
     // 现代检测方式：支持触摸且屏幕较小
diff --git a/be/apps/dashboard/src/components/common/ErrorElement.tsx b/be/apps/dashboard/src/components/common/ErrorElement.tsx
index 8cf993af..7dedac78 100644
--- a/be/apps/dashboard/src/components/common/ErrorElement.tsx
+++ b/be/apps/dashboard/src/components/common/ErrorElement.tsx
@@ -19,21 +19,18 @@ export function ErrorElement() {
   }, [error])
 
   const reloadTriggeredRef = useRef(false)
-  const hasWindow = typeof window !== 'undefined'
   const shouldAttemptReload =
-    hasWindow &&
-    message.startsWith('Failed to fetch dynamically imported module') &&
-    window.sessionStorage.getItem('reload') !== '1'
+    message.startsWith('Failed to fetch dynamically imported module') && window.sessionStorage.getItem('reload') !== '1'
 
   useEffect(() => {
-    if (!shouldAttemptReload || reloadTriggeredRef.current || !hasWindow) {
+    if (!shouldAttemptReload || reloadTriggeredRef.current) {
       return
     }
 
     reloadTriggeredRef.current = true
     window.sessionStorage.setItem('reload', '1')
     window.location.reload()
-  }, [hasWindow, shouldAttemptReload])
+  }, [shouldAttemptReload])
 
   if (shouldAttemptReload) {
     return null
diff --git a/be/apps/dashboard/src/lib/api-client.ts b/be/apps/dashboard/src/lib/api-client.ts
index 1ab943b0..46f61a9d 100644
--- a/be/apps/dashboard/src/lib/api-client.ts
+++ b/be/apps/dashboard/src/lib/api-client.ts
@@ -17,7 +17,7 @@ export const coreApi = $fetch.create({
     setAccessDenied({
       active: true,
       status: 403,
-      path: typeof window !== 'undefined' ? window.location.pathname : current?.path,
+      path: window.location.pathname,
       scope: current?.scope ?? 'api',
       reason: detail,
       source: 'api',
diff --git a/be/apps/dashboard/src/modules/auth/components/SocialAuthButtons.tsx b/be/apps/dashboard/src/modules/auth/components/SocialAuthButtons.tsx
index 07a06f09..a43743b3 100644
--- a/be/apps/dashboard/src/modules/auth/components/SocialAuthButtons.tsx
+++ b/be/apps/dashboard/src/modules/auth/components/SocialAuthButtons.tsx
@@ -33,10 +33,8 @@ export const SocialAuthButtons = memo(function SocialAuthButtons({
     if (callbackURL) {
       return callbackURL
     }
-    if (typeof window !== 'undefined') {
-      return window.location.href
-    }
-    return
+
+    return window.location.href
   }, [callbackURL])
 
   const handleSocialClick = useCallback(
diff --git a/be/apps/dashboard/src/modules/auth/components/SocialConnectionSettings.tsx b/be/apps/dashboard/src/modules/auth/components/SocialConnectionSettings.tsx
index ea2d8552..e69ddada 100644
--- a/be/apps/dashboard/src/modules/auth/components/SocialConnectionSettings.tsx
+++ b/be/apps/dashboard/src/modules/auth/components/SocialConnectionSettings.tsx
@@ -46,11 +46,6 @@ export function SocialConnectionSettings() {
 
   const handleConnect = useCallback(
     async (providerId: string, providerName: string) => {
-      if (typeof window === 'undefined') {
-        toast.error('当前环境不支持 OAuth 绑定')
-        return
-      }
-
       const url = new URL(window.location.href)
       url.searchParams.set('auth-flow', 'link')
       url.searchParams.set('provider', providerId)
diff --git a/be/apps/dashboard/src/modules/auth/hooks/useLogin.ts b/be/apps/dashboard/src/modules/auth/hooks/useLogin.ts
index 3ddc2719..ac3f7218 100644
--- a/be/apps/dashboard/src/modules/auth/hooks/useLogin.ts
+++ b/be/apps/dashboard/src/modules/auth/hooks/useLogin.ts
@@ -25,7 +25,7 @@ export function useLogin() {
   const loginMutation = useMutation({
     mutationFn: async (data: LoginRequest) => {
       if (data.requireRootDomain) {
-        const slug = typeof window !== 'undefined' ? getTenantSlugFromHost(window.location.hostname) : null
+        const slug = getTenantSlugFromHost(window.location.hostname)
         if (slug !== 'root') {
           const rootUrl = buildRootTenantUrl('/root-login')
           window.location.replace(rootUrl)
@@ -56,7 +56,7 @@ export function useLogin() {
       const isSuperAdmin = session.user.role === 'superadmin'
 
       if (tenant && !tenant.isPlaceholder && tenant.slug) {
-        const currentSlug = typeof window !== 'undefined' ? getTenantSlugFromHost(window.location.hostname) : null
+        const currentSlug = getTenantSlugFromHost(window.location.hostname)
         if (!isSuperAdmin && tenant.slug !== currentSlug) {
           try {
             const targetUrl = buildTenantUrl(tenant.slug, '/')
diff --git a/be/apps/dashboard/src/modules/auth/utils/domain.ts b/be/apps/dashboard/src/modules/auth/utils/domain.ts
index 11d1bfdf..22c6063a 100644
--- a/be/apps/dashboard/src/modules/auth/utils/domain.ts
+++ b/be/apps/dashboard/src/modules/auth/utils/domain.ts
@@ -65,10 +65,6 @@ export function buildTenantUrl(slug: string, path = '/'): string {
     throw new Error('Workspace slug is required to build tenant URL.')
   }
 
-  if (typeof window === 'undefined') {
-    throw new TypeError('Cannot build tenant URL outside the browser environment.')
-  }
-
   const { protocol, hostname, port } = window.location
   const baseDomain = resolveBaseDomain(hostname)
 
diff --git a/be/apps/dashboard/src/modules/photos/components/PhotoPage.tsx b/be/apps/dashboard/src/modules/photos/components/PhotoPage.tsx
index 4f8eeadc..82849e2f 100644
--- a/be/apps/dashboard/src/modules/photos/components/PhotoPage.tsx
+++ b/be/apps/dashboard/src/modules/photos/components/PhotoPage.tsx
@@ -44,7 +44,6 @@ const STAGE_ORDER: PhotoSyncProgressStage[] = [
 ]
 
 const MAX_SYNC_LOGS = 200
-const PHOTO_SYNC_RESULT_STORAGE_KEY = 'photo-sync:last-result'
 
 function createInitialStages(totals: PhotoSyncProgressState['totals']): PhotoSyncProgressState['stages'] {
   return STAGE_ORDER.reduce<PhotoSyncProgressState['stages']>(
@@ -73,32 +72,6 @@ export function PhotoPage() {
   const [resolvingConflictId, setResolvingConflictId] = useState<string | null>(null)
   const [syncProgress, setSyncProgress] = useState<PhotoSyncProgressState | null>(null)
 
-  useEffect(() => {
-    if (typeof window === 'undefined') {
-      return
-    }
-
-    const restoreStoredResult = () => {
-      try {
-        const cached = window.sessionStorage.getItem(PHOTO_SYNC_RESULT_STORAGE_KEY)
-        if (!cached) {
-          return
-        }
-
-        const parsed = JSON.parse(cached) as { result?: PhotoSyncResult; lastWasDryRun?: boolean | null }
-        if (parsed?.result) {
-          setResult(parsed.result)
-          setLastWasDryRun(parsed.lastWasDryRun ?? null)
-        }
-      } catch (error) {
-        console.error('Failed to restore cached photo sync result', error)
-        window.sessionStorage.removeItem(PHOTO_SYNC_RESULT_STORAGE_KEY)
-      }
-    }
-
-    restoreStoredResult()
-  }, [])
-
   useEffect(() => {
     setActiveTab(normalizedInitialTab)
   }, [normalizedInitialTab])
@@ -303,16 +276,7 @@ export function PhotoPage() {
       setResult(data)
       setLastWasDryRun(context.dryRun)
       setSyncProgress(null)
-      if (typeof window !== 'undefined') {
-        try {
-          window.sessionStorage.setItem(
-            PHOTO_SYNC_RESULT_STORAGE_KEY,
-            JSON.stringify({ result: data, lastWasDryRun: context.dryRun }),
-          )
-        } catch (error) {
-          console.error('Failed to persist photo sync result snapshot', error)
-        }
-      }
+
       void summaryQuery.refetch()
       void listQuery.refetch()
     },
diff --git a/be/apps/dashboard/src/modules/photos/components/sync/PhotoSyncConflictsPanel.tsx b/be/apps/dashboard/src/modules/photos/components/sync/PhotoSyncConflictsPanel.tsx
index 38b3deb5..82aa1f98 100644
--- a/be/apps/dashboard/src/modules/photos/components/sync/PhotoSyncConflictsPanel.tsx
+++ b/be/apps/dashboard/src/modules/photos/components/sync/PhotoSyncConflictsPanel.tsx
@@ -173,10 +173,6 @@ export function PhotoSyncConflictsPanel({
   }
 
   const confirmAction = (message: string, onConfirm: () => void | Promise<void>) => {
-    if (typeof window === 'undefined') {
-      return onConfirm()
-    }
-
     Prompt.prompt({
       title: '确认操作',
       description: message,
diff --git a/be/apps/dashboard/src/modules/welcome/components/tenant-utils.ts b/be/apps/dashboard/src/modules/welcome/components/tenant-utils.ts
index 21506230..ab0849e2 100644
--- a/be/apps/dashboard/src/modules/welcome/components/tenant-utils.ts
+++ b/be/apps/dashboard/src/modules/welcome/components/tenant-utils.ts
@@ -1,7 +1,4 @@
 export const getCurrentHostname = (): string | null => {
-  if (typeof window === 'undefined') {
-    return null
-  }
   try {
     return window.location.hostname
   } catch {
@@ -10,10 +7,6 @@ export const getCurrentHostname = (): string | null => {
 }
 
 export const buildRegistrationUrl = (): string => {
-  if (typeof window === 'undefined') {
-    return '/platform/welcome'
-  }
-
   try {
     const { protocol, host } = window.location
     return `${protocol}//${host}/platform/welcome`
@@ -23,10 +16,6 @@ export const buildRegistrationUrl = (): string => {
 }
 
 export const buildHomeUrl = (): string => {
-  if (typeof window === 'undefined') {
-    return '/'
-  }
-
   try {
     const { protocol, hostname, port } = window.location
     const normalizedPort = port ? `:${port}` : ''
diff --git a/be/apps/dashboard/src/pages/(onboarding)/login.tsx b/be/apps/dashboard/src/pages/(onboarding)/login.tsx
index 7f7787f1..f97f3669 100644
--- a/be/apps/dashboard/src/pages/(onboarding)/login.tsx
+++ b/be/apps/dashboard/src/pages/(onboarding)/login.tsx
@@ -12,9 +12,6 @@ export function Component() {
   const [password, setPassword] = useState('')
   const { login, isLoading, error, clearError } = useLogin()
   const tenantSlug = useMemo(() => {
-    if (typeof window === 'undefined') {
-      return null
-    }
     return getTenantSlugFromHost(window.location.hostname)
   }, [])
   const showEmailLogin = !tenantSlug
diff --git a/be/apps/dashboard/src/pages/(onboarding)/root-login.tsx b/be/apps/dashboard/src/pages/(onboarding)/root-login.tsx
index cfcd190c..a02d9b3f 100644
--- a/be/apps/dashboard/src/pages/(onboarding)/root-login.tsx
+++ b/be/apps/dashboard/src/pages/(onboarding)/root-login.tsx
@@ -14,9 +14,6 @@ export function Component() {
   const { login, isLoading, error, clearError } = useLogin()
 
   const tenantSlug = useMemo(() => {
-    if (typeof window === 'undefined') {
-      return null
-    }
     return getTenantSlugFromHost(window.location.hostname)
   }, [])
   const rootLoginHref = useMemo(() => {
@@ -33,10 +30,6 @@ export function Component() {
       return
     }
 
-    if (typeof window === 'undefined') {
-      return
-    }
-
     const targetUrl = buildRootTenantUrl('/root-login')
     if (window.location.href === targetUrl) {
       return
@@ -89,9 +82,7 @@ export function Component() {
                   variant="primary"
                   className="w-full"
                   onClick={() => {
-                    if (typeof window !== 'undefined') {
-                      window.location.href = rootLoginHref
-                    }
+                    window.location.href = rootLoginHref
                   }}
                 >
                   Go to root portal
diff --git a/packages/docs/src/App.tsx b/packages/docs/src/App.tsx
index 0e36f4ef..818174ef 100644
--- a/packages/docs/src/App.tsx
+++ b/packages/docs/src/App.tsx
@@ -30,9 +30,8 @@ function App({ url }: { url?: string }) {
       setCurrentPath(path)
       setIsSidebarOpen(false) // 导航后关闭侧边栏
       // 在实际应用中，这里会更新浏览器历史记录
-      if (typeof window !== 'undefined') {
-        window.history.pushState({}, '', path)
-      }
+
+      window.history.pushState({}, '', path)
     },
     [setCurrentPath, setIsSidebarOpen],
   )