diff --git a/frontend/src/App.tsx b/frontend/src/App.tsx
index fbc8bc5..a602b38 100644
--- a/frontend/src/App.tsx
+++ b/frontend/src/App.tsx
@@ -1,6 +1,7 @@
 import { BrowserRouter, Navigate, Route, Routes } from 'react-router-dom'
 import Navbar from './components/Navbar'
 import { AuthProvider, useAuth } from './context/AuthContext'
+import { I18nProvider, useI18n } from './context/I18nContext'
 import CreateTemplatePage from './pages/CreateTemplatePage'
 import DocumentDetailPage from './pages/DocumentDetailPage'
 import DocumentsPage from './pages/DocumentsPage'
@@ -18,7 +19,8 @@ import LogsPage from './pages/LogsPage'
 
 function ProtectedRoute({ children }: { children: React.ReactNode }) {
   const { user, loading } = useAuth()
-  if (loading) return <div className="container"><p>Loading...</p></div>
+  const { t } = useI18n()
+  if (loading) return <div className="container"><p>{t('common.loading')}</p></div>
   if (!user) return <Navigate to="/login" replace />
   return <>{children}</>
 }
@@ -53,9 +55,11 @@ function AppRoutes() {
 export default function App() {
   return (
     <BrowserRouter>
-      <AuthProvider>
-        <AppRoutes />
-      </AuthProvider>
+      <I18nProvider>
+        <AuthProvider>
+          <AppRoutes />
+        </AuthProvider>
+      </I18nProvider>
     </BrowserRouter>
   )
 }
diff --git a/frontend/src/components/AuthShell.tsx b/frontend/src/components/AuthShell.tsx
new file mode 100644
index 0000000..b7b028e
--- /dev/null
+++ b/frontend/src/components/AuthShell.tsx
@@ -0,0 +1,13 @@
+import type { ReactNode } from 'react'
+import LanguageSwitcher from './LanguageSwitcher'
+
+export default function AuthShell({ children }: { children: ReactNode }) {
+  return (
+    <div className="auth-page">
+      <div className="auth-lang-switcher">
+        <LanguageSwitcher compact />
+      </div>
+      {children}
+    </div>
+  )
+}
diff --git a/frontend/src/components/ConfirmDialog.tsx b/frontend/src/components/ConfirmDialog.tsx
index 5bbd18f..eff6aaa 100644
--- a/frontend/src/components/ConfirmDialog.tsx
+++ b/frontend/src/components/ConfirmDialog.tsx
@@ -1,3 +1,5 @@
+import { useI18n } from '../context/I18nContext'
+
 interface ConfirmDialogProps {
   open: boolean
   title: string
@@ -13,12 +15,14 @@ export default function ConfirmDialog({
   open,
   title,
   message,
-  confirmLabel = 'Confirm',
-  cancelLabel = 'Cancel',
+  confirmLabel,
+  cancelLabel,
   danger = false,
   onConfirm,
   onCancel,
 }: ConfirmDialogProps) {
+  const { t } = useI18n()
+
   if (!open) return null
 
   return (
@@ -36,14 +40,14 @@ export default function ConfirmDialog({
         <p style={{ color: 'var(--muted)', marginBottom: 24 }}>{message}</p>
         <div style={{ display: 'flex', gap: 8, justifyContent: 'flex-end' }}>
           <button type="button" className="btn btn-secondary" onClick={onCancel}>
-            {cancelLabel}
+            {cancelLabel ?? t('common.cancel')}
           </button>
           <button
             type="button"
             className={`btn ${danger ? 'btn-danger' : 'btn-primary'}`}
             onClick={onConfirm}
           >
-            {confirmLabel}
+            {confirmLabel ?? t('common.confirm')}
           </button>
         </div>
       </div>
diff --git a/frontend/src/components/LanguageSwitcher.tsx b/frontend/src/components/LanguageSwitcher.tsx
new file mode 100644
index 0000000..acea7b8
--- /dev/null
+++ b/frontend/src/components/LanguageSwitcher.tsx
@@ -0,0 +1,27 @@
+import { useI18n } from '../context/I18nContext'
+import { LOCALES } from '../i18n'
+
+interface LanguageSwitcherProps {
+  compact?: boolean
+}
+
+export default function LanguageSwitcher({ compact = false }: LanguageSwitcherProps) {
+  const { locale, setLocale, t } = useI18n()
+
+  return (
+    <label className={`lang-switcher${compact ? ' lang-switcher-compact' : ''}`}>
+      {!compact && <span className="lang-switcher-label">{t('language.label')}</span>}
+      <select
+        value={locale}
+        onChange={(e) => setLocale(e.target.value as 'en' | 'ru')}
+        aria-label={t('language.label')}
+      >
+        {LOCALES.map((item) => (
+          <option key={item.code} value={item.code}>
+            {item.label}
+          </option>
+        ))}
+      </select>
+    </label>
+  )
+}
diff --git a/frontend/src/components/Navbar.tsx b/frontend/src/components/Navbar.tsx
index cc70194..cfdf431 100644
--- a/frontend/src/components/Navbar.tsx
+++ b/frontend/src/components/Navbar.tsx
@@ -1,8 +1,11 @@
 import { Link, useLocation } from 'react-router-dom'
+import LanguageSwitcher from './LanguageSwitcher'
 import { useAuth } from '../context/AuthContext'
+import { useI18n } from '../context/I18nContext'
 
 export default function Navbar() {
   const { user, logout } = useAuth()
+  const { t } = useI18n()
   const location = useLocation()
 
   const isActive = (path: string) =>
@@ -11,33 +14,34 @@ export default function Navbar() {
   return (
     <nav className="navbar">
       <Link to="/" className="navbar-brand">
-        Document Template Editor
+        {t('nav.brand')}
       </Link>
       <div className="navbar-links">
         <Link to="/templates" className={isActive('/templates') ? 'active' : ''}>
-          Templates
+          {t('nav.templates')}
         </Link>
         <Link to="/documents" className={isActive('/documents') ? 'active' : ''}>
-          Documents
+          {t('nav.documents')}
         </Link>
         {user?.role === 'admin' && (
           <>
             <Link to="/users" className={isActive('/users') ? 'active' : ''}>
-              Users
+              {t('nav.users')}
             </Link>
             <Link to="/logs" className={isActive('/logs') ? 'active' : ''}>
-              Logs
+              {t('nav.logs')}
             </Link>
           </>
         )}
         {user && (
           <>
+            <LanguageSwitcher compact />
             <span>
               {user.username}{' '}
-              <span className={`badge badge-${user.role}`}>{user.role}</span>
+              <span className={`badge badge-${user.role}`}>{t(`roles.${user.role}`)}</span>
             </span>
             <button className="btn btn-secondary btn-sm" onClick={logout}>
-              Logout
+              {t('nav.logout')}
             </button>
           </>
         )}
diff --git a/frontend/src/components/TableRowEditor.tsx b/frontend/src/components/TableRowEditor.tsx
index 0320e0d..debceaa 100644
--- a/frontend/src/components/TableRowEditor.tsx
+++ b/frontend/src/components/TableRowEditor.tsx
@@ -1,4 +1,5 @@
 import type { TemplateVariable } from '../types'
+import { useI18n } from '../context/I18nContext'
 import VariableField from './VariableField'
 
 interface TableRowEditorProps {
@@ -14,6 +15,8 @@ export default function TableRowEditor({
   rows,
   onChange,
 }: TableRowEditorProps) {
+  const { t } = useI18n()
+
   const addRow = () => {
     const newRow: Record<string, unknown> = {}
     childVariables.forEach((v) => {
@@ -39,24 +42,27 @@ export default function TableRowEditor({
 
   return (
     <div className="form-group">
-      <label>{tableVariable.label} (repeating table rows)</label>
+      <label>
+        {tableVariable.label} {t('tableRow.repeatingRows')}
+      </label>
       {tableStyle && (
         <div className="style-hint">
-          Table styles preserved from template ({tableStyle.row_styles?.length ?? 0} reference
-          rows)
+          {t('tableRow.stylesPreserved', {
+            count: tableStyle.row_styles?.length ?? 0,
+          })}
         </div>
       )}
 
       {rows.map((row, rowIndex) => (
         <div key={rowIndex} className="table-row-editor">
           <div className="table-row-editor-header">
-            <strong>Row {rowIndex + 1}</strong>
+            <strong>{t('tableRow.row', { index: rowIndex + 1 })}</strong>
             <button
               type="button"
               className="btn btn-danger btn-sm"
               onClick={() => removeRow(rowIndex)}
             >
-              Remove
+              {t('tableRow.remove')}
             </button>
           </div>
           <div className="table-row-fields">
@@ -73,7 +79,7 @@ export default function TableRowEditor({
       ))}
 
       <button type="button" className="btn btn-secondary" onClick={addRow}>
-        + Add Row
+        {t('tableRow.addRow')}
       </button>
     </div>
   )
diff --git a/frontend/src/components/VariableField.tsx b/frontend/src/components/VariableField.tsx
index 51ba313..18ae6ea 100644
--- a/frontend/src/components/VariableField.tsx
+++ b/frontend/src/components/VariableField.tsx
@@ -1,4 +1,5 @@
 import type { TemplateVariable } from '../types'
+import { useI18n } from '../context/I18nContext'
 
 interface VariableFieldProps {
   variable: TemplateVariable
@@ -7,12 +8,17 @@ interface VariableFieldProps {
 }
 
 export default function VariableField({ variable, value, onChange }: VariableFieldProps) {
+  const { t } = useI18n()
+
   const styleHint = variable.style_params
     ? [
-        variable.style_params.font_name && `Font: ${variable.style_params.font_name}`,
-        variable.style_params.font_size && `Size: ${variable.style_params.font_size}pt`,
-        variable.style_params.bold && 'Bold',
-        variable.style_params.alignment && `Align: ${variable.style_params.alignment}`,
+        variable.style_params.font_name &&
+          t('variableField.font', { name: variable.style_params.font_name }),
+        variable.style_params.font_size &&
+          t('variableField.size', { size: variable.style_params.font_size }),
+        variable.style_params.bold && t('variableField.bold'),
+        variable.style_params.alignment &&
+          t('variableField.align', { align: variable.style_params.alignment }),
       ]
         .filter(Boolean)
         .join(' · ')
@@ -65,7 +71,9 @@ export default function VariableField({ variable, value, onChange }: VariableFie
         {variable.is_required && ' *'}
       </label>
       {renderInput()}
-      {styleHint && <div className="style-hint">Style: {styleHint}</div>}
+      {styleHint && (
+        <div className="style-hint">{t('variableField.style', { hint: styleHint })}</div>
+      )}
     </div>
   )
 }
diff --git a/frontend/src/context/I18nContext.tsx b/frontend/src/context/I18nContext.tsx
new file mode 100644
index 0000000..71a4137
--- /dev/null
+++ b/frontend/src/context/I18nContext.tsx
@@ -0,0 +1,81 @@
+import {
+  createContext,
+  useCallback,
+  useContext,
+  useEffect,
+  useMemo,
+  useState,
+  type ReactNode,
+} from 'react'
+import {
+  interpolate,
+  localeToIntl,
+  LOCALE_STORAGE_KEY,
+  messages,
+  readStoredLocale,
+  getNestedMessage,
+  type Locale,
+} from '../i18n'
+
+type TranslateVars = Record<string, string | number>
+
+interface I18nContextValue {
+  locale: Locale
+  setLocale: (locale: Locale) => void
+  t: (key: string, vars?: TranslateVars) => string
+  formatDate: (value: string | Date) => string
+  formatDateTime: (value: string | Date) => string
+}
+
+const I18nContext = createContext<I18nContextValue | null>(null)
+
+export function I18nProvider({ children }: { children: ReactNode }) {
+  const [locale, setLocaleState] = useState<Locale>(readStoredLocale)
+
+  const setLocale = useCallback((next: Locale) => {
+    setLocaleState(next)
+    localStorage.setItem(LOCALE_STORAGE_KEY, next)
+  }, [])
+
+  useEffect(() => {
+    document.documentElement.lang = locale
+  }, [locale])
+
+  const intlLocale = localeToIntl(locale)
+
+  const t = useCallback(
+    (key: string, vars?: TranslateVars) => {
+      const text =
+        getNestedMessage(messages[locale] as unknown as Record<string, unknown>, key) ??
+        getNestedMessage(messages.en as unknown as Record<string, unknown>, key) ??
+        key
+      return interpolate(text, vars)
+    },
+    [locale],
+  )
+
+  const formatDate = useCallback(
+    (value: string | Date) => new Date(value).toLocaleDateString(intlLocale),
+    [intlLocale],
+  )
+
+  const formatDateTime = useCallback(
+    (value: string | Date) => new Date(value).toLocaleString(intlLocale),
+    [intlLocale],
+  )
+
+  const value = useMemo(
+    () => ({ locale, setLocale, t, formatDate, formatDateTime }),
+    [locale, setLocale, t, formatDate, formatDateTime],
+  )
+
+  return <I18nContext.Provider value={value}>{children}</I18nContext.Provider>
+}
+
+export function useI18n(): I18nContextValue {
+  const ctx = useContext(I18nContext)
+  if (!ctx) {
+    throw new Error('useI18n must be used within I18nProvider')
+  }
+  return ctx
+}
diff --git a/frontend/src/i18n/index.ts b/frontend/src/i18n/index.ts
new file mode 100644
index 0000000..3b83927
--- /dev/null
+++ b/frontend/src/i18n/index.ts
@@ -0,0 +1,46 @@
+import { en } from './locales/en'
+import { ru } from './locales/ru'
+
+export type Locale = 'en' | 'ru'
+
+export const LOCALES: { code: Locale; label: string }[] = [
+  { code: 'en', label: 'English' },
+  { code: 'ru', label: 'Русский' },
+]
+
+export const messages = { en, ru } as const
+
+export const LOCALE_STORAGE_KEY = 'locale'
+
+export function getNestedMessage(obj: Record<string, unknown>, path: string): string | undefined {
+  const parts = path.split('.')
+  let current: unknown = obj
+  for (const part of parts) {
+    if (!current || typeof current !== 'object' || !(part in current)) {
+      return undefined
+    }
+    current = (current as Record<string, unknown>)[part]
+  }
+  return typeof current === 'string' ? current : undefined
+}
+
+export function interpolate(
+  text: string,
+  vars?: Record<string, string | number>,
+): string {
+  if (!vars) return text
+  return text.replace(/\{\{(\w+)\}\}/g, (_, key: string) =>
+    key in vars ? String(vars[key]) : `{{${key}}}`,
+  )
+}
+
+export function localeToIntl(locale: Locale): string {
+  return locale === 'ru' ? 'ru-RU' : 'en-US'
+}
+
+export function readStoredLocale(): Locale {
+  const stored = localStorage.getItem(LOCALE_STORAGE_KEY)
+  if (stored === 'ru' || stored === 'en') return stored
+  const lang = navigator.language.toLowerCase()
+  return lang.startsWith('ru') ? 'ru' : 'en'
+}
diff --git a/frontend/src/i18n/locales/en.ts b/frontend/src/i18n/locales/en.ts
new file mode 100644
index 0000000..e40a054
--- /dev/null
+++ b/frontend/src/i18n/locales/en.ts
@@ -0,0 +1,228 @@
+export const en = {
+  common: {
+    loading: 'Loading...',
+    pleaseWait: 'Please wait...',
+    cancel: 'Cancel',
+    save: 'Save',
+    delete: 'Delete',
+    confirm: 'Confirm',
+    apply: 'Apply',
+    clear: 'Clear',
+    back: 'Back',
+    edit: 'Edit',
+    view: 'View',
+    create: 'Create',
+    actions: 'Actions',
+    name: 'Name',
+    email: 'Email',
+    username: 'Username',
+    password: 'Password',
+    confirmPassword: 'Confirm Password',
+    role: 'Role',
+    yes: 'Yes',
+    no: 'No',
+    notFound: 'Not found',
+    cannotUndo: 'This action cannot be undone.',
+    empty: '—',
+    file: 'File',
+    owner: 'Owner',
+    created: 'Created',
+    active: 'Active',
+    you: '(you)',
+  },
+  roles: {
+    user: 'User',
+    admin: 'Admin',
+  },
+  status: {
+    active: 'active',
+    inactive: 'inactive',
+  },
+  visibility: {
+    public: 'public',
+    private: 'private',
+    publicFull: 'Public (visible to all users)',
+    privateFull: 'Private',
+    makePublic: 'Make Public',
+    makePrivate: 'Make Private',
+  },
+  nav: {
+    brand: 'Document Template Editor',
+    templates: 'Templates',
+    documents: 'Documents',
+    users: 'Users',
+    logs: 'Logs',
+    logout: 'Logout',
+  },
+  language: {
+    label: 'Language',
+    en: 'English',
+    ru: 'Русский',
+  },
+  errors: {
+    loginFailed: 'Login failed',
+    registrationFailed: 'Registration failed',
+    passwordsMismatch: 'Passwords do not match',
+    activationFailed: 'Activation failed',
+    resendFailed: 'Failed to resend code',
+    requestFailed: 'Request failed',
+    resetFailed: 'Reset failed',
+    loadFailed: 'Failed to load',
+    loadTemplatesFailed: 'Failed to load templates',
+    loadUsersFailed: 'Failed to load users',
+    loadLogsFailed: 'Failed to load logs',
+    loadTemplateFailed: 'Failed to load template',
+    loadDocumentFailed: 'Failed to load document',
+    deleteFailed: 'Delete failed',
+    updateFailed: 'Update failed',
+    downloadFailed: 'Download failed',
+    uploadFailed: 'Upload failed',
+    previewFailed: 'Preview failed',
+    saveFailed: 'Save failed',
+    exportFailed: 'Export failed',
+    exportPdfFailed: 'PDF export failed. Install LibreOffice for PDF support.',
+    createUserFailed: 'Failed to create user',
+    actionFailed: 'Action failed',
+    selectDocx: 'Please select a .docx file',
+  },
+  auth: {
+    tagline: 'Upload Jinja2 .docx templates, fill variables, preview and export.',
+    login: 'Login',
+    createAccount: 'Create account',
+    activateAccount: 'Activate account',
+    forgotPassword: 'Forgot password?',
+    registerTitle: 'Create Account',
+    registerHint: 'Register to use document templates. You will receive an activation code by email.',
+    register: 'Register',
+    alreadyHaveAccount: 'Already have an account?',
+    activateTitle: 'Activate Account',
+    activateHint: 'Enter the activation code sent to your email.',
+    activationCode: 'Activation Code',
+    activationCodePlaceholder: '6-digit code',
+    activate: 'Activate',
+    resendCode: 'Resend Code',
+    backToLogin: 'Back to login',
+    forgotTitle: 'Forgot Password',
+    forgotHint: 'Enter your email and we will send a reset code.',
+    sendResetCode: 'Send Reset Code',
+    haveCode: 'Have a code?',
+    resetPasswordLink: 'Reset password',
+    resetTitle: 'Reset Password',
+    resetHint: 'Enter the code from your email and choose a new password.',
+    resetCode: 'Reset Code',
+    newPassword: 'New Password',
+    updatePassword: 'Update Password',
+  },
+  templates: {
+    title: 'Templates',
+    upload: '+ Upload Template',
+    uploadShort: 'Upload Template',
+    empty: 'No templates yet. Upload a .docx file with Jinja2 variables to get started.',
+    visibility: 'Visibility',
+    variables: 'Variables',
+    fill: 'Fill',
+    source: 'Source',
+    deleteTitle: 'Delete template',
+    deleteMessage: 'Delete template "{{name}}"? {{cannotUndo}}',
+    uploadTitle: 'Upload Template',
+    stepUpload: '1. Upload .docx',
+    stepFill: '2. Fill Variables',
+    stepPreview: '3. Preview & Export',
+    templateName: 'Template Name *',
+    description: 'Description',
+    docxFile: '.docx File with Jinja2 Variables *',
+    docxHint: 'Use {{ variable }} for text fields. For repeating table rows use {%tr for item in items %} ... {%tr endfor %}.',
+    makePublic: 'Make template public (visible to all users)',
+    parsing: 'Parsing...',
+    uploadContinue: 'Upload & Continue',
+    useTemplate: 'Use Template',
+    downloadSource: 'Download Source',
+    label: 'Label',
+    type: 'Type',
+    required: 'Required',
+    styleParams: 'Style Parameters',
+    variablesCount: 'Variables ({{count}})',
+    fillTitle: 'Fill: {{name}}',
+    fillHint: 'Reusable template · {{count}} variables detected',
+    documentFields: 'Document Fields',
+    documentName: 'Document Name *',
+    templateInfo: 'Template Info',
+    detectedVariables: 'Detected Variables',
+    style: 'Style',
+    previewDocument: 'Preview Document',
+    rendering: 'Rendering...',
+    editFields: 'Edit Fields',
+    saving: 'Saving...',
+    saveExport: 'Save & Export',
+  },
+  documents: {
+    title: 'Documents',
+    createFromTemplate: 'Create from Template',
+    empty: 'No filled documents yet. Choose a template and fill in the variables.',
+    templateId: 'Template ID',
+    deleteTitle: 'Delete document',
+    deleteMessage: 'Delete document "{{name}}"? {{cannotUndo}}',
+    fromTemplate: 'From template: {{name}}',
+    ownerLine: 'Owner: {{name}}',
+    saved: 'Saved {{date}}',
+    exportDocx: 'Export DOCX',
+    exportPdf: 'Export PDF',
+    reuseTemplate: 'Reuse Template',
+    preview: 'Preview',
+    previewUnavailable: 'Preview unavailable',
+    fieldData: 'Field Data',
+    editTitle: 'Edit Document',
+    templateLine: 'Template: {{name}}',
+    previewBtn: 'Preview',
+    saveChanges: 'Save Changes',
+  },
+  users: {
+    title: 'User Management',
+    addUser: '+ Add User',
+    createUser: 'Create User',
+    editUser: 'Edit User: {{username}}',
+    newPasswordHint: 'New Password (leave empty to keep)',
+    status: 'Status',
+    activate: 'Activate',
+    deactivate: 'Deactivate',
+    activateTitle: 'Activate user',
+    deactivateTitle: 'Deactivate user',
+    activateMessage: 'Activate user "{{username}}"? They will be able to sign in again.',
+    deactivateMessage: 'Deactivate user "{{username}}"? They will no longer be able to sign in.',
+    deleteTitle: 'Delete user',
+    deleteMessage: 'Delete user "{{username}}"? {{cannotUndo}}',
+  },
+  logs: {
+    title: 'Activity Logs',
+    filterByAction: 'Filter by action',
+    filterPlaceholder: 'e.g. user.delete, template.create',
+    time: 'Time',
+    user: 'User',
+    action: 'Action',
+    resource: 'Resource',
+    details: 'Details',
+    ip: 'IP',
+    empty: 'No log entries found',
+  },
+  tableRow: {
+    repeatingRows: '(repeating table rows)',
+    stylesPreserved: 'Table styles preserved from template ({{count}} reference rows)',
+    row: 'Row {{index}}',
+    remove: 'Remove',
+    addRow: '+ Add Row',
+  },
+  variableField: {
+    style: 'Style: {{hint}}',
+    font: 'Font: {{name}}',
+    size: 'Size: {{size}}pt',
+    bold: 'Bold',
+    align: 'Align: {{align}}',
+  },
+} as const
+
+type DeepStringRecord<T> = {
+  [K in keyof T]: T[K] extends string ? string : DeepStringRecord<T[K]>
+}
+
+export type Messages = DeepStringRecord<typeof en>
+export type MessageKey = string
diff --git a/frontend/src/i18n/locales/ru.ts b/frontend/src/i18n/locales/ru.ts
new file mode 100644
index 0000000..c9b5de8
--- /dev/null
+++ b/frontend/src/i18n/locales/ru.ts
@@ -0,0 +1,223 @@
+import type { Messages } from './en'
+
+export const ru: Messages = {
+  common: {
+    loading: 'Загрузка...',
+    pleaseWait: 'Подождите...',
+    cancel: 'Отмена',
+    save: 'Сохранить',
+    delete: 'Удалить',
+    confirm: 'Подтвердить',
+    apply: 'Применить',
+    clear: 'Сбросить',
+    back: 'Назад',
+    edit: 'Изменить',
+    view: 'Просмотр',
+    create: 'Создать',
+    actions: 'Действия',
+    name: 'Название',
+    email: 'Email',
+    username: 'Имя пользователя',
+    password: 'Пароль',
+    confirmPassword: 'Подтверждение пароля',
+    role: 'Роль',
+    yes: 'Да',
+    no: 'Нет',
+    notFound: 'Не найдено',
+    cannotUndo: 'Это действие нельзя отменить.',
+    empty: '—',
+    file: 'Файл',
+    owner: 'Владелец',
+    created: 'Создано',
+    active: 'Активен',
+    you: '(вы)',
+  },
+  roles: {
+    user: 'Пользователь',
+    admin: 'Администратор',
+  },
+  status: {
+    active: 'активен',
+    inactive: 'неактивен',
+  },
+  visibility: {
+    public: 'публичный',
+    private: 'приватный',
+    publicFull: 'Публичный (виден всем пользователям)',
+    privateFull: 'Приватный',
+    makePublic: 'Сделать публичным',
+    makePrivate: 'Сделать приватным',
+  },
+  nav: {
+    brand: 'Редактор шаблонов документов',
+    templates: 'Шаблоны',
+    documents: 'Документы',
+    users: 'Пользователи',
+    logs: 'Журнал',
+    logout: 'Выйти',
+  },
+  language: {
+    label: 'Язык',
+    en: 'English',
+    ru: 'Русский',
+  },
+  errors: {
+    loginFailed: 'Ошибка входа',
+    registrationFailed: 'Ошибка регистрации',
+    passwordsMismatch: 'Пароли не совпадают',
+    activationFailed: 'Ошибка активации',
+    resendFailed: 'Не удалось отправить код повторно',
+    requestFailed: 'Ошибка запроса',
+    resetFailed: 'Ошибка сброса пароля',
+    loadFailed: 'Не удалось загрузить',
+    loadTemplatesFailed: 'Не удалось загрузить шаблоны',
+    loadUsersFailed: 'Не удалось загрузить пользователей',
+    loadLogsFailed: 'Не удалось загрузить журнал',
+    loadTemplateFailed: 'Не удалось загрузить шаблон',
+    loadDocumentFailed: 'Не удалось загрузить документ',
+    deleteFailed: 'Не удалось удалить',
+    updateFailed: 'Не удалось обновить',
+    downloadFailed: 'Не удалось скачать',
+    uploadFailed: 'Не удалось загрузить файл',
+    previewFailed: 'Не удалось создать предпросмотр',
+    saveFailed: 'Не удалось сохранить',
+    exportFailed: 'Не удалось экспортировать',
+    exportPdfFailed: 'Не удалось экспортировать PDF. Установите LibreOffice для поддержки PDF.',
+    createUserFailed: 'Не удалось создать пользователя',
+    actionFailed: 'Действие не выполнено',
+    selectDocx: 'Выберите файл .docx',
+  },
+  auth: {
+    tagline: 'Загружайте шаблоны .docx с Jinja2, заполняйте переменные, просматривайте и экспортируйте.',
+    login: 'Войти',
+    createAccount: 'Создать аккаунт',
+    activateAccount: 'Активировать аккаунт',
+    forgotPassword: 'Забыли пароль?',
+    registerTitle: 'Создание аккаунта',
+    registerHint: 'Зарегистрируйтесь для работы с шаблонами. Код активации будет отправлен на email.',
+    register: 'Зарегистрироваться',
+    alreadyHaveAccount: 'Уже есть аккаунт?',
+    activateTitle: 'Активация аккаунта',
+    activateHint: 'Введите код активации, отправленный на ваш email.',
+    activationCode: 'Код активации',
+    activationCodePlaceholder: '6-значный код',
+    activate: 'Активировать',
+    resendCode: 'Отправить код повторно',
+    backToLogin: 'Вернуться ко входу',
+    forgotTitle: 'Восстановление пароля',
+    forgotHint: 'Введите email — мы отправим код для сброса пароля.',
+    sendResetCode: 'Отправить код',
+    haveCode: 'Уже есть код?',
+    resetPasswordLink: 'Сбросить пароль',
+    resetTitle: 'Сброс пароля',
+    resetHint: 'Введите код из письма и выберите новый пароль.',
+    resetCode: 'Код сброса',
+    newPassword: 'Новый пароль',
+    updatePassword: 'Обновить пароль',
+  },
+  templates: {
+    title: 'Шаблоны',
+    upload: '+ Загрузить шаблон',
+    uploadShort: 'Загрузить шаблон',
+    empty: 'Шаблонов пока нет. Загрузите файл .docx с переменными Jinja2, чтобы начать.',
+    visibility: 'Видимость',
+    variables: 'Переменные',
+    fill: 'Заполнить',
+    source: 'Исходник',
+    deleteTitle: 'Удалить шаблон',
+    deleteMessage: 'Удалить шаблон «{{name}}»? {{cannotUndo}}',
+    uploadTitle: 'Загрузка шаблона',
+    stepUpload: '1. Загрузка .docx',
+    stepFill: '2. Заполнение переменных',
+    stepPreview: '3. Просмотр и экспорт',
+    templateName: 'Название шаблона *',
+    description: 'Описание',
+    docxFile: 'Файл .docx с переменными Jinja2 *',
+    docxHint: 'Используйте {{ variable }} для текстовых полей. Для повторяющихся строк таблицы: {%tr for item in items %} ... {%tr endfor %}.',
+    makePublic: 'Сделать шаблон публичным (виден всем пользователям)',
+    parsing: 'Разбор файла...',
+    uploadContinue: 'Загрузить и продолжить',
+    useTemplate: 'Использовать шаблон',
+    downloadSource: 'Скачать исходник',
+    label: 'Метка',
+    type: 'Тип',
+    required: 'Обязательное',
+    styleParams: 'Параметры стиля',
+    variablesCount: 'Переменные ({{count}})',
+    fillTitle: 'Заполнение: {{name}}',
+    fillHint: 'Многоразовый шаблон · обнаружено переменных: {{count}}',
+    documentFields: 'Поля документа',
+    documentName: 'Название документа *',
+    templateInfo: 'Информация о шаблоне',
+    detectedVariables: 'Обнаруженные переменные',
+    style: 'Стиль',
+    previewDocument: 'Предпросмотр документа',
+    rendering: 'Формирование...',
+    editFields: 'Изменить поля',
+    saving: 'Сохранение...',
+    saveExport: 'Сохранить и экспортировать',
+  },
+  documents: {
+    title: 'Документы',
+    createFromTemplate: 'Создать из шаблона',
+    empty: 'Заполненных документов пока нет. Выберите шаблон и заполните переменные.',
+    templateId: 'ID шаблона',
+    deleteTitle: 'Удалить документ',
+    deleteMessage: 'Удалить документ «{{name}}»? {{cannotUndo}}',
+    fromTemplate: 'Из шаблона: {{name}}',
+    ownerLine: 'Владелец: {{name}}',
+    saved: 'Сохранено {{date}}',
+    exportDocx: 'Экспорт DOCX',
+    exportPdf: 'Экспорт PDF',
+    reuseTemplate: 'Использовать шаблон снова',
+    preview: 'Предпросмотр',
+    previewUnavailable: 'Предпросмотр недоступен',
+    fieldData: 'Данные полей',
+    editTitle: 'Редактирование документа',
+    templateLine: 'Шаблон: {{name}}',
+    previewBtn: 'Предпросмотр',
+    saveChanges: 'Сохранить изменения',
+  },
+  users: {
+    title: 'Управление пользователями',
+    addUser: '+ Добавить пользователя',
+    createUser: 'Создать пользователя',
+    editUser: 'Редактирование: {{username}}',
+    newPasswordHint: 'Новый пароль (оставьте пустым, чтобы не менять)',
+    status: 'Статус',
+    activate: 'Активировать',
+    deactivate: 'Деактивировать',
+    activateTitle: 'Активация пользователя',
+    deactivateTitle: 'Деактивация пользователя',
+    activateMessage: 'Активировать пользователя «{{username}}»? Он снова сможет входить в систему.',
+    deactivateMessage: 'Деактивировать пользователя «{{username}}»? Он больше не сможет входить в систему.',
+    deleteTitle: 'Удалить пользователя',
+    deleteMessage: 'Удалить пользователя «{{username}}»? {{cannotUndo}}',
+  },
+  logs: {
+    title: 'Журнал действий',
+    filterByAction: 'Фильтр по действию',
+    filterPlaceholder: 'напр. user.delete, template.create',
+    time: 'Время',
+    user: 'Пользователь',
+    action: 'Действие',
+    resource: 'Ресурс',
+    details: 'Подробности',
+    ip: 'IP',
+    empty: 'Записей не найдено',
+  },
+  tableRow: {
+    repeatingRows: '(повторяющиеся строки таблицы)',
+    stylesPreserved: 'Стили таблицы сохранены из шаблона ({{count}} эталонных строк)',
+    row: 'Строка {{index}}',
+    remove: 'Удалить',
+    addRow: '+ Добавить строку',
+  },
+  variableField: {
+    style: 'Стиль: {{hint}}',
+    font: 'Шрифт: {{name}}',
+    size: 'Размер: {{size}}pt',
+    bold: 'Жирный',
+    align: 'Выравнивание: {{align}}',
+  },
+}
diff --git a/frontend/src/index.css b/frontend/src/index.css
index 0b92599..143724a 100644
--- a/frontend/src/index.css
+++ b/frontend/src/index.css
@@ -309,6 +309,7 @@ textarea {
 }
 
 .auth-page {
+  position: relative;
   min-height: 100vh;
   display: flex;
   align-items: center;
@@ -379,6 +380,36 @@ textarea {
   color: var(--success);
 }
 
+.lang-switcher {
+  display: inline-flex;
+  align-items: center;
+  gap: 8px;
+  font-size: 0.9rem;
+}
+
+.lang-switcher-label {
+  color: var(--muted);
+}
+
+.lang-switcher select {
+  padding: 6px 10px;
+  border: 1px solid var(--border);
+  border-radius: 8px;
+  background: white;
+  cursor: pointer;
+}
+
+.lang-switcher-compact select {
+  padding: 4px 8px;
+  font-size: 0.85rem;
+}
+
+.auth-lang-switcher {
+  position: absolute;
+  top: 16px;
+  right: 16px;
+}
+
 .dialog-overlay {
   position: fixed;
   inset: 0;
diff --git a/frontend/src/pages/ActivatePage.tsx b/frontend/src/pages/ActivatePage.tsx
index 1080941..7334151 100644
--- a/frontend/src/pages/ActivatePage.tsx
+++ b/frontend/src/pages/ActivatePage.tsx
@@ -1,10 +1,13 @@
 import { useState } from 'react'
 import { Link, useLocation, useNavigate } from 'react-router-dom'
 import { api } from '../api'
+import AuthShell from '../components/AuthShell'
+import { useI18n } from '../context/I18nContext'
 
 export default function ActivatePage() {
   const navigate = useNavigate()
   const location = useLocation()
+  const { t } = useI18n()
   const initialEmail = (location.state as { email?: string } | null)?.email ?? ''
 
   const [email, setEmail] = useState(initialEmail)
@@ -23,7 +26,7 @@ export default function ActivatePage() {
       setSuccess(result.message)
       setTimeout(() => navigate('/login'), 1500)
     } catch (err) {
-      setError(err instanceof Error ? err.message : 'Activation failed')
+      setError(err instanceof Error ? err.message : t('errors.activationFailed'))
     } finally {
       setLoading(false)
     }
@@ -36,22 +39,22 @@ export default function ActivatePage() {
       const result = await api.resendActivation(email)
       setSuccess(result.message)
     } catch (err) {
-      setError(err instanceof Error ? err.message : 'Failed to resend code')
+      setError(err instanceof Error ? err.message : t('errors.resendFailed'))
     }
   }
 
   return (
-    <div className="auth-page">
+    <AuthShell>
       <div className="card auth-card">
-        <h1>Activate Account</h1>
-        <p>Enter the activation code sent to your email.</p>
+        <h1>{t('auth.activateTitle')}</h1>
+        <p>{t('auth.activateHint')}</p>
 
         {error && <div className="error">{error}</div>}
         {success && <div className="success">{success}</div>}
 
         <form onSubmit={handleActivate}>
           <div className="form-group">
-            <label>Email</label>
+            <label>{t('common.email')}</label>
             <input
               type="email"
               value={email}
@@ -60,16 +63,16 @@ export default function ActivatePage() {
             />
           </div>
           <div className="form-group">
-            <label>Activation Code</label>
+            <label>{t('auth.activationCode')}</label>
             <input
               value={code}
               onChange={(e) => setCode(e.target.value)}
               required
-              placeholder="6-digit code"
+              placeholder={t('auth.activationCodePlaceholder')}
             />
           </div>
           <button type="submit" className="btn btn-primary" style={{ width: '100%' }} disabled={loading}>
-            {loading ? 'Please wait...' : 'Activate'}
+            {loading ? t('common.pleaseWait') : t('auth.activate')}
           </button>
         </form>
 
@@ -80,13 +83,13 @@ export default function ActivatePage() {
           onClick={handleResend}
           disabled={!email}
         >
-          Resend Code
+          {t('auth.resendCode')}
         </button>
 
         <p style={{ marginTop: 16 }}>
-          <Link to="/login">Back to login</Link>
+          <Link to="/login">{t('auth.backToLogin')}</Link>
         </p>
       </div>
-    </div>
+    </AuthShell>
   )
 }
diff --git a/frontend/src/pages/CreateTemplatePage.tsx b/frontend/src/pages/CreateTemplatePage.tsx
index 3874d51..ca1f66b 100644
--- a/frontend/src/pages/CreateTemplatePage.tsx
+++ b/frontend/src/pages/CreateTemplatePage.tsx
@@ -1,9 +1,11 @@
 import { useState } from 'react'
 import { useNavigate } from 'react-router-dom'
 import { api } from '../api'
+import { useI18n } from '../context/I18nContext'
 
 export default function CreateTemplatePage() {
   const navigate = useNavigate()
+  const { t } = useI18n()
   const [name, setName] = useState('')
   const [description, setDescription] = useState('')
   const [file, setFile] = useState<File | null>(null)
@@ -14,7 +16,7 @@ export default function CreateTemplatePage() {
   const handleSubmit = async (e: React.FormEvent) => {
     e.preventDefault()
     if (!file) {
-      setError('Please select a .docx file')
+      setError(t('errors.selectDocx'))
       return
     }
     setError('')
@@ -28,7 +30,7 @@ export default function CreateTemplatePage() {
       )
       navigate(`/templates/${template.id}/fill`)
     } catch (err) {
-      setError(err instanceof Error ? err.message : 'Upload failed')
+      setError(err instanceof Error ? err.message : t('errors.uploadFailed'))
     } finally {
       setLoading(false)
     }
@@ -37,13 +39,13 @@ export default function CreateTemplatePage() {
   return (
     <div className="container">
       <div className="page-header">
-        <h1>Upload Template</h1>
+        <h1>{t('templates.uploadTitle')}</h1>
       </div>
 
       <div className="steps">
-        <div className="step active">1. Upload .docx</div>
-        <div className="step">2. Fill Variables</div>
-        <div className="step">3. Preview & Export</div>
+        <div className="step active">{t('templates.stepUpload')}</div>
+        <div className="step">{t('templates.stepFill')}</div>
+        <div className="step">{t('templates.stepPreview')}</div>
       </div>
 
       <div className="card" style={{ maxWidth: 600 }}>
@@ -51,11 +53,11 @@ export default function CreateTemplatePage() {
 
         <form onSubmit={handleSubmit}>
           <div className="form-group">
-            <label>Template Name *</label>
+            <label>{t('templates.templateName')}</label>
             <input value={name} onChange={(e) => setName(e.target.value)} required />
           </div>
           <div className="form-group">
-            <label>Description</label>
+            <label>{t('templates.description')}</label>
             <textarea
               value={description}
               onChange={(e) => setDescription(e.target.value)}
@@ -63,7 +65,7 @@ export default function CreateTemplatePage() {
             />
           </div>
           <div className="form-group">
-            <label>.docx File with Jinja2 Variables *</label>
+            <label>{t('templates.docxFile')}</label>
             <input
               type="file"
               accept=".docx"
@@ -71,8 +73,7 @@ export default function CreateTemplatePage() {
               required
             />
             <div className="style-hint" style={{ marginTop: 8 }}>
-              Use {'{{ variable }}'} for text fields. For repeating table rows use{' '}
-              {'{%tr for item in items %}'} ... {'{%tr endfor %}'}.
+              {t('templates.docxHint')}
             </div>
           </div>
           <div className="form-group">
@@ -83,19 +84,19 @@ export default function CreateTemplatePage() {
                 onChange={(e) => setIsPublic(e.target.checked)}
                 style={{ width: 'auto', marginRight: 8 }}
               />
-              Make template public (visible to all users)
+              {t('templates.makePublic')}
             </label>
           </div>
           <div style={{ display: 'flex', gap: 12 }}>
             <button type="submit" className="btn btn-primary" disabled={loading}>
-              {loading ? 'Parsing...' : 'Upload & Continue'}
+              {loading ? t('templates.parsing') : t('templates.uploadContinue')}
             </button>
             <button
               type="button"
               className="btn btn-secondary"
               onClick={() => navigate('/templates')}
             >
-              Cancel
+              {t('common.cancel')}
             </button>
           </div>
         </form>
diff --git a/frontend/src/pages/DocumentDetailPage.tsx b/frontend/src/pages/DocumentDetailPage.tsx
index ac2ade4..fcfe8de 100644
--- a/frontend/src/pages/DocumentDetailPage.tsx
+++ b/frontend/src/pages/DocumentDetailPage.tsx
@@ -3,12 +3,14 @@ import { Link, useNavigate, useParams } from 'react-router-dom'
 import { api, downloadWithAuth } from '../api'
 import ConfirmDialog from '../components/ConfirmDialog'
 import { useAuth } from '../context/AuthContext'
+import { useI18n } from '../context/I18nContext'
 import type { DocumentTemplate, FilledDocument } from '../types'
 
 export default function DocumentDetailPage() {
   const { id } = useParams<{ id: string }>()
   const navigate = useNavigate()
   const { user } = useAuth()
+  const { t, formatDateTime } = useI18n()
   const [document, setDocument] = useState<FilledDocument | null>(null)
   const [template, setTemplate] = useState<DocumentTemplate | null>(null)
   const [previewHtml, setPreviewHtml] = useState<string | null>(null)
@@ -21,8 +23,8 @@ export default function DocumentDetailPage() {
       try {
         const doc = await api.getDocument(Number(id))
         setDocument(doc)
-        const t = await api.getTemplate(doc.template_id)
-        setTemplate(t)
+        const loadedTemplate = await api.getTemplate(doc.template_id)
+        setTemplate(loadedTemplate)
         const preview = await api.previewDocument({
           template_id: doc.template_id,
           name: doc.name,
@@ -30,7 +32,7 @@ export default function DocumentDetailPage() {
         })
         setPreviewHtml(preview.html)
       } catch (err) {
-        setError(err instanceof Error ? err.message : 'Failed to load')
+        setError(err instanceof Error ? err.message : t('errors.loadFailed'))
       } finally {
         setLoading(false)
       }
@@ -46,7 +48,7 @@ export default function DocumentDetailPage() {
         `${document.name}.docx`,
       )
     } catch (err) {
-      alert(err instanceof Error ? err.message : 'Export failed')
+      alert(err instanceof Error ? err.message : t('errors.exportFailed'))
     }
   }
 
@@ -58,7 +60,7 @@ export default function DocumentDetailPage() {
         `${document.name}.pdf`,
       )
     } catch (err) {
-      alert(err instanceof Error ? err.message : 'PDF export failed. Install LibreOffice for PDF support.')
+      alert(err instanceof Error ? err.message : t('errors.exportPdfFailed'))
     }
   }
 
@@ -68,23 +70,26 @@ export default function DocumentDetailPage() {
       await api.deleteDocument(document.id)
       navigate('/documents')
     } catch (err) {
-      alert(err instanceof Error ? err.message : 'Delete failed')
+      alert(err instanceof Error ? err.message : t('errors.deleteFailed'))
     }
   }
 
   const canManage =
     user?.role === 'admin' || document?.owner_id === user?.id
 
-  if (loading) return <div className="container"><p>Loading...</p></div>
+  if (loading) return <div className="container"><p>{t('common.loading')}</p></div>
   if (!document) return <div className="container"><div className="error">{error}</div></div>
 
   return (
     <div className="container">
       <ConfirmDialog
         open={showDeleteConfirm}
-        title="Delete document"
-        message={`Delete document "${document.name}"? This action cannot be undone.`}
-        confirmLabel="Delete"
+        title={t('documents.deleteTitle')}
+        message={t('documents.deleteMessage', {
+          name: document.name,
+          cannotUndo: t('common.cannotUndo'),
+        })}
+        confirmLabel={t('common.delete')}
         danger
         onConfirm={() => void handleDelete()}
         onCancel={() => setShowDeleteConfirm(false)}
@@ -95,30 +100,31 @@ export default function DocumentDetailPage() {
           <h1>{document.name}</h1>
           {template && (
             <div className="style-hint">
-              From template: {template.name}
-              {document.owner_username && ` · Owner: ${document.owner_username}`}
-              {' · '}Saved {new Date(document.created_at).toLocaleString()}
+              {t('documents.fromTemplate', { name: template.name })}
+              {document.owner_username && ` · ${t('documents.ownerLine', { name: document.owner_username })}`}
+              {' · '}
+              {t('documents.saved', { date: formatDateTime(document.created_at) })}
             </div>
           )}
         </div>
         <div style={{ display: 'flex', gap: 8, flexWrap: 'wrap' }}>
           <button className="btn btn-primary" onClick={handleExportDocx}>
-            Export DOCX
+            {t('documents.exportDocx')}
           </button>
           <button className="btn btn-secondary" onClick={handleExportPdf}>
-            Export PDF
+            {t('documents.exportPdf')}
           </button>
           <Link to={`/documents/${document.id}/edit`} className="btn btn-secondary">
-            Edit
+            {t('common.edit')}
           </Link>
           {template && (
             <Link to={`/templates/${template.id}/fill`} className="btn btn-secondary">
-              Reuse Template
+              {t('documents.reuseTemplate')}
             </Link>
           )}
           {canManage && (
             <button className="btn btn-danger" onClick={() => setShowDeleteConfirm(true)}>
-              Delete
+              {t('common.delete')}
             </button>
           )}
         </div>
@@ -128,19 +134,19 @@ export default function DocumentDetailPage() {
 
       <div className="grid-2">
         <div className="card">
-          <h2 style={{ marginTop: 0 }}>Preview</h2>
+          <h2 style={{ marginTop: 0 }}>{t('documents.preview')}</h2>
           {previewHtml ? (
             <div
               className="doc-preview"
               dangerouslySetInnerHTML={{ __html: previewHtml }}
             />
           ) : (
-            <p>Preview unavailable</p>
+            <p>{t('documents.previewUnavailable')}</p>
           )}
         </div>
 
         <div className="card">
-          <h2 style={{ marginTop: 0 }}>Field Data</h2>
+          <h2 style={{ marginTop: 0 }}>{t('documents.fieldData')}</h2>
           <pre style={{
             background: '#f8fafc',
             padding: 16,
diff --git a/frontend/src/pages/DocumentsPage.tsx b/frontend/src/pages/DocumentsPage.tsx
index 69425b0..2e6b7e3 100644
--- a/frontend/src/pages/DocumentsPage.tsx
+++ b/frontend/src/pages/DocumentsPage.tsx
@@ -3,10 +3,12 @@ import { Link } from 'react-router-dom'
 import { api } from '../api'
 import ConfirmDialog from '../components/ConfirmDialog'
 import { useAuth } from '../context/AuthContext'
+import { useI18n } from '../context/I18nContext'
 import type { FilledDocument } from '../types'
 
 export default function DocumentsPage() {
   const { user } = useAuth()
+  const { t, formatDateTime } = useI18n()
   const [documents, setDocuments] = useState<FilledDocument[]>([])
   const [loading, setLoading] = useState(true)
   const [error, setError] = useState('')
@@ -15,7 +17,7 @@ export default function DocumentsPage() {
   const load = () => {
     api.listDocuments()
       .then(setDocuments)
-      .catch((err) => setError(err instanceof Error ? err.message : 'Failed to load'))
+      .catch((err) => setError(err instanceof Error ? err.message : t('errors.loadFailed')))
       .finally(() => setLoading(false))
   }
 
@@ -30,7 +32,7 @@ export default function DocumentsPage() {
       setDocuments((list) => list.filter((d) => d.id !== deleteTarget.id))
       setDeleteTarget(null)
     } catch (err) {
-      alert(err instanceof Error ? err.message : 'Delete failed')
+      alert(err instanceof Error ? err.message : t('errors.deleteFailed'))
     }
   }
 
@@ -40,43 +42,46 @@ export default function DocumentsPage() {
     <div className="container">
       <ConfirmDialog
         open={deleteTarget !== null}
-        title="Delete document"
+        title={t('documents.deleteTitle')}
         message={
           deleteTarget
-            ? `Delete document "${deleteTarget.name}"? This action cannot be undone.`
+            ? t('documents.deleteMessage', {
+                name: deleteTarget.name,
+                cannotUndo: t('common.cannotUndo'),
+              })
             : ''
         }
-        confirmLabel="Delete"
+        confirmLabel={t('common.delete')}
         danger
         onConfirm={() => void handleDelete()}
         onCancel={() => setDeleteTarget(null)}
       />
 
       <div className="page-header">
-        <h1>Documents</h1>
+        <h1>{t('documents.title')}</h1>
         <Link to="/templates" className="btn btn-primary">
-          Create from Template
+          {t('documents.createFromTemplate')}
         </Link>
       </div>
 
       {error && <div className="error">{error}</div>}
 
       {loading ? (
-        <p>Loading...</p>
+        <p>{t('common.loading')}</p>
       ) : documents.length === 0 ? (
         <div className="card empty-state">
-          <p>No filled documents yet. Choose a template and fill in the variables.</p>
+          <p>{t('documents.empty')}</p>
         </div>
       ) : (
         <div className="card">
           <table className="table">
             <thead>
               <tr>
-                <th>Name</th>
-                {isAdmin && <th>Owner</th>}
-                <th>Template ID</th>
-                <th>Created</th>
-                <th>Actions</th>
+                <th>{t('common.name')}</th>
+                {isAdmin && <th>{t('common.owner')}</th>}
+                <th>{t('documents.templateId')}</th>
+                <th>{t('common.created')}</th>
+                <th>{t('common.actions')}</th>
               </tr>
             </thead>
             <tbody>
@@ -85,20 +90,20 @@ export default function DocumentsPage() {
                   <td><strong>{d.name}</strong></td>
                   {isAdmin && <td>{d.owner_username ?? `#${d.owner_id}`}</td>}
                   <td>{d.template_id}</td>
-                  <td>{new Date(d.created_at).toLocaleString()}</td>
+                  <td>{formatDateTime(d.created_at)}</td>
                   <td style={{ display: 'flex', gap: 8 }}>
                     <Link to={`/documents/${d.id}`} className="btn btn-primary btn-sm">
-                      View
+                      {t('common.view')}
                     </Link>
                     <Link to={`/documents/${d.id}/edit`} className="btn btn-secondary btn-sm">
-                      Edit
+                      {t('common.edit')}
                     </Link>
                     {(isAdmin || d.owner_id === user?.id) && (
                       <button
                         className="btn btn-danger btn-sm"
                         onClick={() => setDeleteTarget(d)}
                       >
-                        Delete
+                        {t('common.delete')}
                       </button>
                     )}
                   </td>
diff --git a/frontend/src/pages/EditDocumentPage.tsx b/frontend/src/pages/EditDocumentPage.tsx
index 8bdc234..6b8598d 100644
--- a/frontend/src/pages/EditDocumentPage.tsx
+++ b/frontend/src/pages/EditDocumentPage.tsx
@@ -3,11 +3,13 @@ import { Link, useNavigate, useParams } from 'react-router-dom'
 import { api } from '../api'
 import TableRowEditor from '../components/TableRowEditor'
 import VariableField from '../components/VariableField'
+import { useI18n } from '../context/I18nContext'
 import type { DocumentTemplate } from '../types'
 
 export default function EditDocumentPage() {
   const { id } = useParams<{ id: string }>()
   const navigate = useNavigate()
+  const { t } = useI18n()
   const [template, setTemplate] = useState<DocumentTemplate | null>(null)
   const [fieldData, setFieldData] = useState<Record<string, unknown>>({})
   const [documentName, setDocumentName] = useState('')
@@ -21,12 +23,12 @@ export default function EditDocumentPage() {
     const load = async () => {
       try {
         const doc = await api.getDocument(Number(id))
-        const t = await api.getTemplate(doc.template_id)
-        setTemplate(t)
+        const loadedTemplate = await api.getTemplate(doc.template_id)
+        setTemplate(loadedTemplate)
         setDocumentName(doc.name)
         setFieldData(doc.field_data)
       } catch (err) {
-        setError(err instanceof Error ? err.message : 'Failed to load document')
+        setError(err instanceof Error ? err.message : t('errors.loadDocumentFailed'))
       } finally {
         setLoading(false)
       }
@@ -64,7 +66,7 @@ export default function EditDocumentPage() {
       setPreviewHtml(result.html)
       setStep(3)
     } catch (err) {
-      setError(err instanceof Error ? err.message : 'Preview failed')
+      setError(err instanceof Error ? err.message : t('errors.previewFailed'))
     } finally {
       setSubmitting(false)
     }
@@ -81,23 +83,23 @@ export default function EditDocumentPage() {
       })
       navigate(`/documents/${doc.id}`)
     } catch (err) {
-      setError(err instanceof Error ? err.message : 'Save failed')
+      setError(err instanceof Error ? err.message : t('errors.saveFailed'))
     } finally {
       setSubmitting(false)
     }
   }
 
-  if (loading) return <div className="container"><p>Loading...</p></div>
-  if (!template) return <div className="container"><div className="error">{error || 'Not found'}</div></div>
+  if (loading) return <div className="container"><p>{t('common.loading')}</p></div>
+  if (!template) return <div className="container"><div className="error">{error || t('common.notFound')}</div></div>
 
   return (
     <div className="container">
       <div className="page-header">
         <div>
-          <h1>Edit Document</h1>
-          <div className="style-hint">Template: {template.name}</div>
+          <h1>{t('documents.editTitle')}</h1>
+          <div className="style-hint">{t('documents.templateLine', { name: template.name })}</div>
         </div>
-        <Link to={`/documents/${id}`} className="btn btn-secondary">Back</Link>
+        <Link to={`/documents/${id}`} className="btn btn-secondary">{t('common.back')}</Link>
       </div>
 
       {error && <div className="error">{error}</div>}
@@ -105,7 +107,7 @@ export default function EditDocumentPage() {
       {step === 2 && (
         <div className="card" style={{ maxWidth: 720 }}>
           <div className="form-group">
-            <label>Document Name *</label>
+            <label>{t('templates.documentName')}</label>
             <input
               value={documentName}
               onChange={(e) => setDocumentName(e.target.value)}
@@ -146,7 +148,7 @@ export default function EditDocumentPage() {
               onClick={handlePreview}
               disabled={submitting}
             >
-              {submitting ? 'Rendering...' : 'Preview'}
+              {submitting ? t('templates.rendering') : t('documents.previewBtn')}
             </button>
           </div>
         </div>
@@ -162,14 +164,14 @@ export default function EditDocumentPage() {
           </div>
           <div style={{ display: 'flex', gap: 12 }}>
             <button className="btn btn-secondary" onClick={() => setStep(2)}>
-              Edit Fields
+              {t('templates.editFields')}
             </button>
             <button
               className="btn btn-primary"
               onClick={handleSave}
               disabled={submitting}
             >
-              {submitting ? 'Saving...' : 'Save Changes'}
+              {submitting ? t('templates.saving') : t('documents.saveChanges')}
             </button>
           </div>
         </div>
diff --git a/frontend/src/pages/FillTemplatePage.tsx b/frontend/src/pages/FillTemplatePage.tsx
index dce971a..def6735 100644
--- a/frontend/src/pages/FillTemplatePage.tsx
+++ b/frontend/src/pages/FillTemplatePage.tsx
@@ -3,11 +3,13 @@ import { Link, useNavigate, useParams } from 'react-router-dom'
 import { api } from '../api'
 import TableRowEditor from '../components/TableRowEditor'
 import VariableField from '../components/VariableField'
+import { useI18n } from '../context/I18nContext'
 import type { DocumentTemplate } from '../types'
 
 export default function FillTemplatePage() {
   const { id } = useParams<{ id: string }>()
   const navigate = useNavigate()
+  const { t } = useI18n()
   const [template, setTemplate] = useState<DocumentTemplate | null>(null)
   const [fieldData, setFieldData] = useState<Record<string, unknown>>({})
   const [documentName, setDocumentName] = useState('')
@@ -20,12 +22,12 @@ export default function FillTemplatePage() {
   useEffect(() => {
     const load = async () => {
       try {
-        const t = await api.getTemplate(Number(id))
-        setTemplate(t)
-        setDocumentName(`${t.name} - ${new Date().toLocaleDateString()}`)
+        const loaded = await api.getTemplate(Number(id))
+        setTemplate(loaded)
+        setDocumentName(`${loaded.name} - ${new Date().toLocaleDateString()}`)
 
         const initial: Record<string, unknown> = {}
-        t.variables.forEach((v) => {
+        loaded.variables.forEach((v) => {
           if (v.field_type === 'table_row') {
             initial[v.name] = []
           } else if (!v.parent_variable) {
@@ -34,7 +36,7 @@ export default function FillTemplatePage() {
         })
         setFieldData(initial)
       } catch (err) {
-        setError(err instanceof Error ? err.message : 'Failed to load template')
+        setError(err instanceof Error ? err.message : t('errors.loadTemplateFailed'))
       } finally {
         setLoading(false)
       }
@@ -72,7 +74,7 @@ export default function FillTemplatePage() {
       setPreviewHtml(result.html)
       setStep(3)
     } catch (err) {
-      setError(err instanceof Error ? err.message : 'Preview failed')
+      setError(err instanceof Error ? err.message : t('errors.previewFailed'))
     } finally {
       setSubmitting(false)
     }
@@ -90,29 +92,31 @@ export default function FillTemplatePage() {
       })
       navigate(`/documents/${doc.id}`)
     } catch (err) {
-      setError(err instanceof Error ? err.message : 'Save failed')
+      setError(err instanceof Error ? err.message : t('errors.saveFailed'))
     } finally {
       setSubmitting(false)
     }
   }
 
-  if (loading) return <div className="container"><p>Loading...</p></div>
-  if (!template) return <div className="container"><div className="error">{error || 'Not found'}</div></div>
+  if (loading) return <div className="container"><p>{t('common.loading')}</p></div>
+  if (!template) return <div className="container"><div className="error">{error || t('common.notFound')}</div></div>
 
   return (
     <div className="container">
       <div className="page-header">
         <div>
-          <h1>Fill: {template.name}</h1>
-          <div className="style-hint">Reusable template · {template.variables.length} variables detected</div>
+          <h1>{t('templates.fillTitle', { name: template.name })}</h1>
+          <div className="style-hint">
+            {t('templates.fillHint', { count: template.variables.length })}
+          </div>
         </div>
-        <Link to="/templates" className="btn btn-secondary">Back</Link>
+        <Link to="/templates" className="btn btn-secondary">{t('common.back')}</Link>
       </div>
 
       <div className="steps">
-        <div className="step done">1. Upload .docx</div>
-        <div className={`step ${step === 2 ? 'active' : step > 2 ? 'done' : ''}`}>2. Fill Variables</div>
-        <div className={`step ${step === 3 ? 'active' : ''}`}>3. Preview & Export</div>
+        <div className="step done">{t('templates.stepUpload')}</div>
+        <div className={`step ${step === 2 ? 'active' : step > 2 ? 'done' : ''}`}>{t('templates.stepFill')}</div>
+        <div className={`step ${step === 3 ? 'active' : ''}`}>{t('templates.stepPreview')}</div>
       </div>
 
       {error && <div className="error">{error}</div>}
@@ -120,10 +124,10 @@ export default function FillTemplatePage() {
       {step === 2 && (
         <div className="grid-2">
           <div className="card">
-            <h2 style={{ marginTop: 0 }}>Document Fields</h2>
+            <h2 style={{ marginTop: 0 }}>{t('templates.documentFields')}</h2>
 
             <div className="form-group">
-              <label>Document Name *</label>
+              <label>{t('templates.documentName')}</label>
               <input
                 value={documentName}
                 onChange={(e) => setDocumentName(e.target.value)}
@@ -164,22 +168,22 @@ export default function FillTemplatePage() {
                 onClick={handlePreview}
                 disabled={submitting}
               >
-                {submitting ? 'Rendering...' : 'Preview Document'}
+                {submitting ? t('templates.rendering') : t('templates.previewDocument')}
               </button>
             </div>
           </div>
 
           <div className="card">
-            <h2 style={{ marginTop: 0 }}>Template Info</h2>
-            <p><strong>File:</strong> {template.original_filename}</p>
+            <h2 style={{ marginTop: 0 }}>{t('templates.templateInfo')}</h2>
+            <p><strong>{t('common.file')}:</strong> {template.original_filename}</p>
             {template.description && <p>{template.description}</p>}
-            <h3>Detected Variables</h3>
+            <h3>{t('templates.detectedVariables')}</h3>
             <table className="table">
               <thead>
                 <tr>
-                  <th>Name</th>
-                  <th>Type</th>
-                  <th>Style</th>
+                  <th>{t('common.name')}</th>
+                  <th>{t('templates.type')}</th>
+                  <th>{t('templates.style')}</th>
                 </tr>
               </thead>
               <tbody>
@@ -188,7 +192,7 @@ export default function FillTemplatePage() {
                     <td>{v.name}</td>
                     <td>{v.field_type}</td>
                     <td className="style-hint">
-                      {v.style_params?.font_name ?? '—'}
+                      {v.style_params?.font_name ?? t('common.empty')}
                       {v.style_params?.alignment ? ` / ${v.style_params.alignment}` : ''}
                     </td>
                   </tr>
@@ -209,14 +213,14 @@ export default function FillTemplatePage() {
           </div>
           <div style={{ display: 'flex', gap: 12 }}>
             <button className="btn btn-secondary" onClick={() => setStep(2)}>
-              Edit Fields
+              {t('templates.editFields')}
             </button>
             <button
               className="btn btn-primary"
               onClick={handleSave}
               disabled={submitting}
             >
-              {submitting ? 'Saving...' : 'Save & Export'}
+              {submitting ? t('templates.saving') : t('templates.saveExport')}
             </button>
           </div>
         </div>
diff --git a/frontend/src/pages/ForgotPasswordPage.tsx b/frontend/src/pages/ForgotPasswordPage.tsx
index fb5df69..7878d59 100644
--- a/frontend/src/pages/ForgotPasswordPage.tsx
+++ b/frontend/src/pages/ForgotPasswordPage.tsx
@@ -1,8 +1,11 @@
 import { useState } from 'react'
 import { Link } from 'react-router-dom'
 import { api } from '../api'
+import AuthShell from '../components/AuthShell'
+import { useI18n } from '../context/I18nContext'
 
 export default function ForgotPasswordPage() {
+  const { t } = useI18n()
   const [email, setEmail] = useState('')
   const [error, setError] = useState('')
   const [success, setSuccess] = useState('')
@@ -17,24 +20,24 @@ export default function ForgotPasswordPage() {
       const result = await api.forgotPassword(email)
       setSuccess(result.message)
     } catch (err) {
-      setError(err instanceof Error ? err.message : 'Request failed')
+      setError(err instanceof Error ? err.message : t('errors.requestFailed'))
     } finally {
       setLoading(false)
     }
   }
 
   return (
-    <div className="auth-page">
+    <AuthShell>
       <div className="card auth-card">
-        <h1>Forgot Password</h1>
-        <p>Enter your email and we will send a reset code.</p>
+        <h1>{t('auth.forgotTitle')}</h1>
+        <p>{t('auth.forgotHint')}</p>
 
         {error && <div className="error">{error}</div>}
         {success && <div className="success">{success}</div>}
 
         <form onSubmit={handleSubmit}>
           <div className="form-group">
-            <label>Email</label>
+            <label>{t('common.email')}</label>
             <input
               type="email"
               value={email}
@@ -43,17 +46,17 @@ export default function ForgotPasswordPage() {
             />
           </div>
           <button type="submit" className="btn btn-primary" style={{ width: '100%' }} disabled={loading}>
-            {loading ? 'Please wait...' : 'Send Reset Code'}
+            {loading ? t('common.pleaseWait') : t('auth.sendResetCode')}
           </button>
         </form>
 
         <p style={{ marginTop: 16 }}>
-          Have a code? <Link to="/reset-password">Reset password</Link>
+          {t('auth.haveCode')} <Link to="/reset-password">{t('auth.resetPasswordLink')}</Link>
         </p>
         <p>
-          <Link to="/login">Back to login</Link>
+          <Link to="/login">{t('auth.backToLogin')}</Link>
         </p>
       </div>
-    </div>
+    </AuthShell>
   )
 }
diff --git a/frontend/src/pages/LoginPage.tsx b/frontend/src/pages/LoginPage.tsx
index 8257379..8fcf0c7 100644
--- a/frontend/src/pages/LoginPage.tsx
+++ b/frontend/src/pages/LoginPage.tsx
@@ -1,9 +1,12 @@
 import { useState } from 'react'
 import { Link, Navigate } from 'react-router-dom'
+import AuthShell from '../components/AuthShell'
 import { useAuth } from '../context/AuthContext'
+import { useI18n } from '../context/I18nContext'
 
 export default function LoginPage() {
   const { user, login } = useAuth()
+  const { t } = useI18n()
   const [username, setUsername] = useState('')
   const [password, setPassword] = useState('')
   const [error, setError] = useState('')
@@ -18,23 +21,23 @@ export default function LoginPage() {
     try {
       await login(username, password)
     } catch (err) {
-      setError(err instanceof Error ? err.message : 'Login failed')
+      setError(err instanceof Error ? err.message : t('errors.loginFailed'))
     } finally {
       setLoading(false)
     }
   }
 
   return (
-    <div className="auth-page">
+    <AuthShell>
       <div className="card auth-card">
-        <h1>Document Template Editor</h1>
-        <p>Upload Jinja2 .docx templates, fill variables, preview and export.</p>
+        <h1>{t('nav.brand')}</h1>
+        <p>{t('auth.tagline')}</p>
 
         {error && <div className="error">{error}</div>}
 
         <form onSubmit={handleSubmit}>
           <div className="form-group">
-            <label>Username</label>
+            <label>{t('common.username')}</label>
             <input
               value={username}
               onChange={(e) => setUsername(e.target.value)}
@@ -42,7 +45,7 @@ export default function LoginPage() {
             />
           </div>
           <div className="form-group">
-            <label>Password</label>
+            <label>{t('common.password')}</label>
             <input
               type="password"
               value={password}
@@ -51,22 +54,22 @@ export default function LoginPage() {
             />
           </div>
           <button type="submit" className="btn btn-primary" style={{ width: '100%' }} disabled={loading}>
-            {loading ? 'Please wait...' : 'Login'}
+            {loading ? t('common.pleaseWait') : t('auth.login')}
           </button>
         </form>
 
         <div style={{ marginTop: 20, fontSize: '0.9rem' }}>
           <p style={{ margin: '8px 0' }}>
-            <Link to="/register">Create account</Link>
+            <Link to="/register">{t('auth.createAccount')}</Link>
           </p>
           <p style={{ margin: '8px 0' }}>
-            <Link to="/activate">Activate account</Link>
+            <Link to="/activate">{t('auth.activateAccount')}</Link>
           </p>
           <p style={{ margin: '8px 0' }}>
-            <Link to="/forgot-password">Forgot password?</Link>
+            <Link to="/forgot-password">{t('auth.forgotPassword')}</Link>
           </p>
         </div>
       </div>
-    </div>
+    </AuthShell>
   )
 }
diff --git a/frontend/src/pages/LogsPage.tsx b/frontend/src/pages/LogsPage.tsx
index df0cb66..9648f6f 100644
--- a/frontend/src/pages/LogsPage.tsx
+++ b/frontend/src/pages/LogsPage.tsx
@@ -2,20 +2,25 @@ import { useEffect, useState } from 'react'
 import { Navigate } from 'react-router-dom'
 import { api } from '../api'
 import { useAuth } from '../context/AuthContext'
+import { useI18n } from '../context/I18nContext'
 import type { AuditLog } from '../types'
 
 function formatAction(action: string): string {
   return action.replace(/\./g, ' · ').replace(/_/g, ' ')
 }
 
-function formatDetails(details: Record<string, unknown> | null): string {
-  if (!details) return '—'
+function formatDetails(
+  details: Record<string, unknown> | null,
+  emptyLabel: string,
+): string {
+  if (!details) return emptyLabel
   const text = JSON.stringify(details, null, 0)
   return text.length > 120 ? `${text.slice(0, 120)}…` : text
 }
 
 export default function LogsPage() {
   const { user: currentUser } = useAuth()
+  const { t, formatDateTime } = useI18n()
   const [logs, setLogs] = useState<AuditLog[]>([])
   const [loading, setLoading] = useState(true)
   const [error, setError] = useState('')
@@ -27,7 +32,7 @@ export default function LogsPage() {
     try {
       setLogs(await api.listLogs({ action: action || undefined }))
     } catch (err) {
-      setError(err instanceof Error ? err.message : 'Failed to load logs')
+      setError(err instanceof Error ? err.message : t('errors.loadLogsFailed'))
     } finally {
       setLoading(false)
     }
@@ -49,21 +54,21 @@ export default function LogsPage() {
   return (
     <div className="container">
       <div className="page-header">
-        <h1>Activity Logs</h1>
+        <h1>{t('logs.title')}</h1>
       </div>
 
       <form onSubmit={handleFilter} className="card" style={{ marginBottom: 24 }}>
         <div style={{ display: 'flex', gap: 12, alignItems: 'flex-end', flexWrap: 'wrap' }}>
           <div className="form-group" style={{ marginBottom: 0, flex: '1 1 240px' }}>
-            <label>Filter by action</label>
+            <label>{t('logs.filterByAction')}</label>
             <input
               value={actionFilter}
               onChange={(e) => setActionFilter(e.target.value)}
-              placeholder="e.g. user.delete, template.create"
+              placeholder={t('logs.filterPlaceholder')}
             />
           </div>
           <button type="submit" className="btn btn-primary">
-            Apply
+            {t('common.apply')}
           </button>
           <button
             type="button"
@@ -73,7 +78,7 @@ export default function LogsPage() {
               load()
             }}
           >
-            Clear
+            {t('common.clear')}
           </button>
         </div>
       </form>
@@ -81,48 +86,48 @@ export default function LogsPage() {
       {error && <div className="error">{error}</div>}
 
       {loading ? (
-        <p>Loading...</p>
+        <p>{t('common.loading')}</p>
       ) : (
         <div className="card" style={{ overflowX: 'auto' }}>
           <table className="table">
             <thead>
               <tr>
-                <th>Time</th>
-                <th>User</th>
-                <th>Action</th>
-                <th>Resource</th>
-                <th>Details</th>
-                <th>IP</th>
+                <th>{t('logs.time')}</th>
+                <th>{t('logs.user')}</th>
+                <th>{t('logs.action')}</th>
+                <th>{t('logs.resource')}</th>
+                <th>{t('logs.details')}</th>
+                <th>{t('logs.ip')}</th>
               </tr>
             </thead>
             <tbody>
               {logs.length === 0 ? (
                 <tr>
                   <td colSpan={6} style={{ textAlign: 'center', color: 'var(--muted)' }}>
-                    No log entries found
+                    {t('logs.empty')}
                   </td>
                 </tr>
               ) : (
                 logs.map((log) => (
                   <tr key={log.id}>
                     <td style={{ whiteSpace: 'nowrap' }}>
-                      {new Date(log.created_at).toLocaleString()}
+                      {formatDateTime(log.created_at)}
                     </td>
-                    <td>{log.username || '—'}</td>
+                    <td>{log.username || t('common.empty')}</td>
                     <td>
                       <code className="log-action">{formatAction(log.action)}</code>
                     </td>
                     <td>
                       {log.resource_type
                         ? `${log.resource_type}${log.resource_id != null ? ` #${log.resource_id}` : ''}`
-                        : '—'}
+                        : t('common.empty')}
                     </td>
                     <td>
                       <span className="style-hint" title={JSON.stringify(log.details, null, 2)}>
-                        {formatDetails(log.details)}
+                        {formatDetails(log.details, t('common.empty'))}
                       </span>
                     </td>
-                    <td>{log.ip_address || '—'}</td>
+                    <td>{log.ip_address || t('common.empty')}</td>
                   </tr>
                 ))
               )}
diff --git a/frontend/src/pages/RegisterPage.tsx b/frontend/src/pages/RegisterPage.tsx
index 72b946d..c089fa3 100644
--- a/frontend/src/pages/RegisterPage.tsx
+++ b/frontend/src/pages/RegisterPage.tsx
@@ -1,10 +1,13 @@
 import { useState } from 'react'
 import { Link, useNavigate } from 'react-router-dom'
+import AuthShell from '../components/AuthShell'
 import { useAuth } from '../context/AuthContext'
+import { useI18n } from '../context/I18nContext'
 
 export default function RegisterPage() {
   const { register } = useAuth()
   const navigate = useNavigate()
+  const { t } = useI18n()
   const [email, setEmail] = useState('')
   const [username, setUsername] = useState('')
   const [password, setPassword] = useState('')
@@ -19,7 +22,7 @@ export default function RegisterPage() {
     setSuccess('')
 
     if (password !== confirmPassword) {
-      setError('Passwords do not match')
+      setError(t('errors.passwordsMismatch'))
       return
     }
 
@@ -31,24 +34,24 @@ export default function RegisterPage() {
         navigate('/activate', { state: { email: result.email } })
       }, 1500)
     } catch (err) {
-      setError(err instanceof Error ? err.message : 'Registration failed')
+      setError(err instanceof Error ? err.message : t('errors.registrationFailed'))
     } finally {
       setLoading(false)
     }
   }
 
   return (
-    <div className="auth-page">
+    <AuthShell>
       <div className="card auth-card">
-        <h1>Create Account</h1>
-        <p>Register to use document templates. You will receive an activation code by email.</p>
+        <h1>{t('auth.registerTitle')}</h1>
+        <p>{t('auth.registerHint')}</p>
 
         {error && <div className="error">{error}</div>}
         {success && <div className="success">{success}</div>}
 
         <form onSubmit={handleSubmit}>
           <div className="form-group">
-            <label>Email</label>
+            <label>{t('common.email')}</label>
             <input
               type="email"
               value={email}
@@ -57,7 +60,7 @@ export default function RegisterPage() {
             />
           </div>
           <div className="form-group">
-            <label>Username</label>
+            <label>{t('common.username')}</label>
             <input
               value={username}
               onChange={(e) => setUsername(e.target.value)}
@@ -66,7 +69,7 @@ export default function RegisterPage() {
             />
           </div>
           <div className="form-group">
-            <label>Password</label>
+            <label>{t('common.password')}</label>
             <input
               type="password"
               value={password}
@@ -76,7 +79,7 @@ export default function RegisterPage() {
             />
           </div>
           <div className="form-group">
-            <label>Confirm Password</label>
+            <label>{t('common.confirmPassword')}</label>
             <input
               type="password"
               value={confirmPassword}
@@ -86,14 +89,14 @@ export default function RegisterPage() {
             />
           </div>
           <button type="submit" className="btn btn-primary" style={{ width: '100%' }} disabled={loading}>
-            {loading ? 'Please wait...' : 'Register'}
+            {loading ? t('common.pleaseWait') : t('auth.register')}
           </button>
         </form>
 
         <p style={{ marginTop: 16 }}>
-          Already have an account? <Link to="/login">Login</Link>
+          {t('auth.alreadyHaveAccount')} <Link to="/login">{t('auth.login')}</Link>
         </p>
       </div>
-    </div>
+    </AuthShell>
   )
 }
diff --git a/frontend/src/pages/ResetPasswordPage.tsx b/frontend/src/pages/ResetPasswordPage.tsx
index ed2dc6b..eb43b37 100644
--- a/frontend/src/pages/ResetPasswordPage.tsx
+++ b/frontend/src/pages/ResetPasswordPage.tsx
@@ -1,9 +1,12 @@
 import { useState } from 'react'
 import { Link, useNavigate } from 'react-router-dom'
 import { api } from '../api'
+import AuthShell from '../components/AuthShell'
+import { useI18n } from '../context/I18nContext'
 
 export default function ResetPasswordPage() {
   const navigate = useNavigate()
+  const { t } = useI18n()
   const [email, setEmail] = useState('')
   const [code, setCode] = useState('')
   const [password, setPassword] = useState('')
@@ -18,7 +21,7 @@ export default function ResetPasswordPage() {
     setSuccess('')
 
     if (password !== confirmPassword) {
-      setError('Passwords do not match')
+      setError(t('errors.passwordsMismatch'))
       return
     }
 
@@ -33,24 +36,24 @@ export default function ResetPasswordPage() {
       setSuccess(result.message)
       setTimeout(() => navigate('/login'), 1500)
     } catch (err) {
-      setError(err instanceof Error ? err.message : 'Reset failed')
+      setError(err instanceof Error ? err.message : t('errors.resetFailed'))
     } finally {
       setLoading(false)
     }
   }
 
   return (
-    <div className="auth-page">
+    <AuthShell>
       <div className="card auth-card">
-        <h1>Reset Password</h1>
-        <p>Enter the code from your email and choose a new password.</p>
+        <h1>{t('auth.resetTitle')}</h1>
+        <p>{t('auth.resetHint')}</p>
 
         {error && <div className="error">{error}</div>}
         {success && <div className="success">{success}</div>}
 
         <form onSubmit={handleSubmit}>
           <div className="form-group">
-            <label>Email</label>
+            <label>{t('common.email')}</label>
             <input
               type="email"
               value={email}
@@ -59,7 +62,7 @@ export default function ResetPasswordPage() {
             />
           </div>
           <div className="form-group">
-            <label>Reset Code</label>
+            <label>{t('auth.resetCode')}</label>
             <input
               value={code}
               onChange={(e) => setCode(e.target.value)}
@@ -67,7 +70,7 @@ export default function ResetPasswordPage() {
             />
           </div>
           <div className="form-group">
-            <label>New Password</label>
+            <label>{t('auth.newPassword')}</label>
             <input
               type="password"
               value={password}
@@ -77,7 +80,7 @@ export default function ResetPasswordPage() {
             />
           </div>
           <div className="form-group">
-            <label>Confirm Password</label>
+            <label>{t('common.confirmPassword')}</label>
             <input
               type="password"
               value={confirmPassword}
@@ -87,14 +90,14 @@ export default function ResetPasswordPage() {
             />
           </div>
           <button type="submit" className="btn btn-primary" style={{ width: '100%' }} disabled={loading}>
-            {loading ? 'Please wait...' : 'Update Password'}
+            {loading ? t('common.pleaseWait') : t('auth.updatePassword')}
           </button>
         </form>
 
         <p style={{ marginTop: 16 }}>
-          <Link to="/login">Back to login</Link>
+          <Link to="/login">{t('auth.backToLogin')}</Link>
         </p>
       </div>
-    </div>
+    </AuthShell>
   )
 }
diff --git a/frontend/src/pages/TemplateDetailPage.tsx b/frontend/src/pages/TemplateDetailPage.tsx
index 51207e0..dbafc9f 100644
--- a/frontend/src/pages/TemplateDetailPage.tsx
+++ b/frontend/src/pages/TemplateDetailPage.tsx
@@ -2,11 +2,13 @@ import { useEffect, useState } from 'react'
 import { Link, useParams } from 'react-router-dom'
 import { api, downloadWithAuth } from '../api'
 import { useAuth } from '../context/AuthContext'
+import { useI18n } from '../context/I18nContext'
 import type { DocumentTemplate } from '../types'
 
 export default function TemplateDetailPage() {
   const { id } = useParams<{ id: string }>()
   const { user } = useAuth()
+  const { t, formatDateTime } = useI18n()
   const [template, setTemplate] = useState<DocumentTemplate | null>(null)
   const [error, setError] = useState('')
   const [loading, setLoading] = useState(true)
@@ -14,7 +16,7 @@ export default function TemplateDetailPage() {
   useEffect(() => {
     api.getTemplate(Number(id))
       .then(setTemplate)
-      .catch((err) => setError(err instanceof Error ? err.message : 'Failed to load'))
+      .catch((err) => setError(err instanceof Error ? err.message : t('errors.loadFailed')))
       .finally(() => setLoading(false))
   }, [id])
 
@@ -26,7 +28,7 @@ export default function TemplateDetailPage() {
       })
       setTemplate(updated)
     } catch (err) {
-      alert(err instanceof Error ? err.message : 'Update failed')
+      alert(err instanceof Error ? err.message : t('errors.updateFailed'))
     }
   }
 
@@ -38,11 +40,11 @@ export default function TemplateDetailPage() {
         template.original_filename,
       )
     } catch (err) {
-      alert(err instanceof Error ? err.message : 'Download failed')
+      alert(err instanceof Error ? err.message : t('errors.downloadFailed'))
     }
   }
 
-  if (loading) return <div className="container"><p>Loading...</p></div>
+  if (loading) return <div className="container"><p>{t('common.loading')}</p></div>
   if (!template) return <div className="container"><div className="error">{error}</div></div>
 
   const canManage = template.is_owner || user?.role === 'admin'
@@ -53,38 +55,38 @@ export default function TemplateDetailPage() {
         <h1>{template.name}</h1>
         <div style={{ display: 'flex', gap: 8 }}>
           <Link to={`/templates/${template.id}/fill`} className="btn btn-primary">
-            Use Template
+            {t('templates.useTemplate')}
           </Link>
           <button className="btn btn-secondary" onClick={handleDownloadSource}>
-            Download Source
+            {t('templates.downloadSource')}
           </button>
           {canManage && (
             <button className="btn btn-secondary" onClick={handleTogglePublic}>
-              {template.is_public ? 'Make Private' : 'Make Public'}
+              {template.is_public ? t('visibility.makePrivate') : t('visibility.makePublic')}
             </button>
           )}
         </div>
       </div>
 
       <div className="card">
-        <p><strong>File:</strong> {template.original_filename}</p>
-        <p><strong>Owner:</strong> {template.owner_username ?? `#${template.owner_id}`}</p>
+        <p><strong>{t('common.file')}:</strong> {template.original_filename}</p>
+        <p><strong>{t('common.owner')}:</strong> {template.owner_username ?? `#${template.owner_id}`}</p>
         <p>
-          <strong>Visibility:</strong>{' '}
-          {template.is_public ? 'Public (visible to all users)' : 'Private'}
+          <strong>{t('templates.visibility')}:</strong>{' '}
+          {template.is_public ? t('visibility.publicFull') : t('visibility.privateFull')}
         </p>
         {template.description && <p>{template.description}</p>}
-        <p><strong>Created:</strong> {new Date(template.created_at).toLocaleString()}</p>
+        <p><strong>{t('common.created')}:</strong> {formatDateTime(template.created_at)}</p>
 
-        <h2>Variables ({template.variables.length})</h2>
+        <h2>{t('templates.variablesCount', { count: template.variables.length })}</h2>
         <table className="table">
           <thead>
             <tr>
-              <th>Label</th>
-              <th>Name</th>
-              <th>Type</th>
-              <th>Required</th>
-              <th>Style Parameters</th>
+              <th>{t('templates.label')}</th>
+              <th>{t('common.name')}</th>
+              <th>{t('templates.type')}</th>
+              <th>{t('templates.required')}</th>
+              <th>{t('templates.styleParams')}</th>
             </tr>
           </thead>
           <tbody>
@@ -93,11 +95,11 @@ export default function TemplateDetailPage() {
                 <td>{v.label}</td>
                 <td><code>{v.name}</code></td>
                 <td>{v.field_type}</td>
-                <td>{v.is_required ? 'Yes' : 'No'}</td>
+                <td>{v.is_required ? t('common.yes') : t('common.no')}</td>
                 <td className="style-hint">
                   {v.style_params
                     ? JSON.stringify(v.style_params, null, 0).slice(0, 80) + '...'
-                    : '—'}
+                    : t('common.empty')}
                 </td>
               </tr>
             ))}
diff --git a/frontend/src/pages/TemplatesPage.tsx b/frontend/src/pages/TemplatesPage.tsx
index acddc82..d420837 100644
--- a/frontend/src/pages/TemplatesPage.tsx
+++ b/frontend/src/pages/TemplatesPage.tsx
@@ -3,10 +3,12 @@ import { Link } from 'react-router-dom'
 import { api, downloadWithAuth } from '../api'
 import ConfirmDialog from '../components/ConfirmDialog'
 import { useAuth } from '../context/AuthContext'
+import { useI18n } from '../context/I18nContext'
 import type { TemplateListItem } from '../types'
 
 export default function TemplatesPage() {
   const { user } = useAuth()
+  const { t, formatDate } = useI18n()
   const [templates, setTemplates] = useState<TemplateListItem[]>([])
   const [loading, setLoading] = useState(true)
   const [error, setError] = useState('')
@@ -16,7 +18,7 @@ export default function TemplatesPage() {
     try {
       setTemplates(await api.listTemplates())
     } catch (err) {
-      setError(err instanceof Error ? err.message : 'Failed to load templates')
+      setError(err instanceof Error ? err.message : t('errors.loadTemplatesFailed'))
     } finally {
       setLoading(false)
     }
@@ -33,71 +35,69 @@ export default function TemplatesPage() {
       setTemplates((list) => list.filter((x) => x.id !== deleteTarget.id))
       setDeleteTarget(null)
     } catch (err) {
-      alert(err instanceof Error ? err.message : 'Delete failed')
+      alert(err instanceof Error ? err.message : t('errors.deleteFailed'))
     }
   }
 
-  const handleTogglePublic = async (t: TemplateListItem) => {
+  const handleTogglePublic = async (item: TemplateListItem) => {
     try {
-      const updated = await api.updateTemplate(t.id, { is_public: !t.is_public })
+      const updated = await api.updateTemplate(item.id, { is_public: !item.is_public })
       setTemplates((list) =>
         list.map((x) =>
-          x.id === t.id
-            ? { ...x, is_public: updated.is_public }
-            : x,
+          x.id === item.id ? { ...x, is_public: updated.is_public } : x,
         ),
       )
     } catch (err) {
-      alert(err instanceof Error ? err.message : 'Update failed')
+      alert(err instanceof Error ? err.message : t('errors.updateFailed'))
     }
   }
 
-  const handleDownloadSource = async (t: TemplateListItem) => {
+  const handleDownloadSource = async (item: TemplateListItem) => {
     try {
-      await downloadWithAuth(
-        api.getTemplateSourceUrl(t.id),
-        t.original_filename,
-      )
+      await downloadWithAuth(api.getTemplateSourceUrl(item.id), item.original_filename)
     } catch (err) {
-      alert(err instanceof Error ? err.message : 'Download failed')
+      alert(err instanceof Error ? err.message : t('errors.downloadFailed'))
     }
   }
 
-  const canManage = (t: TemplateListItem) =>
-    t.is_owner || user?.role === 'admin'
+  const canManage = (item: TemplateListItem) =>
+    item.is_owner || user?.role === 'admin'
 
   return (
     <div className="container">
       <ConfirmDialog
         open={deleteTarget !== null}
-        title="Delete template"
+        title={t('templates.deleteTitle')}
         message={
           deleteTarget
-            ? `Delete template "${deleteTarget.name}"? This action cannot be undone.`
+            ? t('templates.deleteMessage', {
+                name: deleteTarget.name,
+                cannotUndo: t('common.cannotUndo'),
+              })
             : ''
         }
-        confirmLabel="Delete"
+        confirmLabel={t('common.delete')}
         danger
         onConfirm={() => void handleDelete()}
         onCancel={() => setDeleteTarget(null)}
       />
 
       <div className="page-header">
-        <h1>Templates</h1>
+        <h1>{t('templates.title')}</h1>
         <Link to="/templates/new" className="btn btn-primary">
-          + Upload Template
+          {t('templates.upload')}
         </Link>
       </div>
 
       {error && <div className="error">{error}</div>}
 
       {loading ? (
-        <p>Loading...</p>
+        <p>{t('common.loading')}</p>
       ) : templates.length === 0 ? (
         <div className="card empty-state">
-          <p>No templates yet. Upload a .docx file with Jinja2 variables to get started.</p>
+          <p>{t('templates.empty')}</p>
           <Link to="/templates/new" className="btn btn-primary" style={{ marginTop: 16 }}>
-            Upload Template
+            {t('templates.uploadShort')}
           </Link>
         </div>
       ) : (
@@ -105,63 +105,63 @@ export default function TemplatesPage() {
           <table className="table">
             <thead>
               <tr>
-                <th>Name</th>
-                <th>File</th>
-                <th>Owner</th>
-                <th>Visibility</th>
-                <th>Variables</th>
-                <th>Created</th>
-                <th>Actions</th>
+                <th>{t('common.name')}</th>
+                <th>{t('common.file')}</th>
+                <th>{t('common.owner')}</th>
+                <th>{t('templates.visibility')}</th>
+                <th>{t('templates.variables')}</th>
+                <th>{t('common.created')}</th>
+                <th>{t('common.actions')}</th>
               </tr>
             </thead>
             <tbody>
-              {templates.map((t) => (
-                <tr key={t.id}>
+              {templates.map((item) => (
+                <tr key={item.id}>
                   <td>
-                    <strong>{t.name}</strong>
-                    {t.description && (
-                      <div className="style-hint">{t.description}</div>
+                    <strong>{item.name}</strong>
+                    {item.description && (
+                      <div className="style-hint">{item.description}</div>
                     )}
                   </td>
-                  <td>{t.original_filename}</td>
-                  <td>{t.owner_username ?? `#${t.owner_id}`}</td>
+                  <td>{item.original_filename}</td>
+                  <td>{item.owner_username ?? `#${item.owner_id}`}</td>
                   <td>
-                    {t.is_public ? (
+                    {item.is_public ? (
                       <span className="badge" style={{ background: '#dbeafe', color: '#1d4ed8' }}>
-                        public
+                        {t('visibility.public')}
                       </span>
                     ) : (
-                      <span className="badge badge-user">private</span>
+                      <span className="badge badge-user">{t('visibility.private')}</span>
                     )}
                   </td>
-                  <td>{t.variable_count}</td>
-                  <td>{new Date(t.created_at).toLocaleDateString()}</td>
+                  <td>{item.variable_count}</td>
+                  <td>{formatDate(item.created_at)}</td>
                   <td style={{ display: 'flex', gap: 8, flexWrap: 'wrap' }}>
-                    <Link to={`/templates/${t.id}/fill`} className="btn btn-primary btn-sm">
-                      Fill
+                    <Link to={`/templates/${item.id}/fill`} className="btn btn-primary btn-sm">
+                      {t('templates.fill')}
                     </Link>
-                    <Link to={`/templates/${t.id}`} className="btn btn-secondary btn-sm">
-                      View
+                    <Link to={`/templates/${item.id}`} className="btn btn-secondary btn-sm">
+                      {t('common.view')}
                     </Link>
                     <button
                       className="btn btn-secondary btn-sm"
-                      onClick={() => handleDownloadSource(t)}
+                      onClick={() => handleDownloadSource(item)}
                     >
-                      Source
+                      {t('templates.source')}
                     </button>
-                    {canManage(t) && (
+                    {canManage(item) && (
                       <>
                         <button
                           className="btn btn-secondary btn-sm"
-                          onClick={() => handleTogglePublic(t)}
+                          onClick={() => handleTogglePublic(item)}
                         >
-                          {t.is_public ? 'Make Private' : 'Make Public'}
+                          {item.is_public ? t('visibility.makePrivate') : t('visibility.makePublic')}
                         </button>
                         <button
                           className="btn btn-danger btn-sm"
-                          onClick={() => setDeleteTarget(t)}
+                          onClick={() => setDeleteTarget(item)}
                         >
-                          Delete
+                          {t('common.delete')}
                         </button>
                       </>
                     )}
diff --git a/frontend/src/pages/UsersPage.tsx b/frontend/src/pages/UsersPage.tsx
index 15c0407..6e56943 100644
--- a/frontend/src/pages/UsersPage.tsx
+++ b/frontend/src/pages/UsersPage.tsx
@@ -3,6 +3,7 @@ import { Navigate } from 'react-router-dom'
 import { api } from '../api'
 import ConfirmDialog from '../components/ConfirmDialog'
 import { useAuth } from '../context/AuthContext'
+import { useI18n } from '../context/I18nContext'
 import type { User } from '../types'
 
 type PendingConfirm = {
@@ -15,6 +16,7 @@ type PendingConfirm = {
 
 export default function UsersPage() {
   const { user: currentUser } = useAuth()
+  const { t, formatDate } = useI18n()
   const [users, setUsers] = useState<User[]>([])
   const [loading, setLoading] = useState(true)
   const [error, setError] = useState('')
@@ -39,7 +41,7 @@ export default function UsersPage() {
     try {
       setUsers(await api.listUsers())
     } catch (err) {
-      setError(err instanceof Error ? err.message : 'Failed to load users')
+      setError(err instanceof Error ? err.message : t('errors.loadUsersFailed'))
     } finally {
       setLoading(false)
     }
@@ -58,7 +60,7 @@ export default function UsersPage() {
       setShowForm(false)
       await load()
     } catch (err) {
-      setError(err instanceof Error ? err.message : 'Failed to create user')
+      setError(err instanceof Error ? err.message : t('errors.createUserFailed'))
     }
   }
 
@@ -87,7 +89,7 @@ export default function UsersPage() {
       setEditingUser(null)
       await load()
     } catch (err) {
-      setError(err instanceof Error ? err.message : 'Update failed')
+      setError(err instanceof Error ? err.message : t('errors.updateFailed'))
     }
   }
 
@@ -98,11 +100,11 @@ export default function UsersPage() {
     if (editForm.is_active !== editingUser.is_active) {
       const activating = editForm.is_active
       setPendingConfirm({
-        title: activating ? 'Activate user' : 'Deactivate user',
+        title: activating ? t('users.activateTitle') : t('users.deactivateTitle'),
         message: activating
-          ? `Activate user "${editingUser.username}"? They will be able to sign in again.`
-          : `Deactivate user "${editingUser.username}"? They will no longer be able to sign in.`,
-        confirmLabel: activating ? 'Activate' : 'Deactivate',
+          ? t('users.activateMessage', { username: editingUser.username })
+          : t('users.deactivateMessage', { username: editingUser.username }),
+        confirmLabel: activating ? t('users.activate') : t('users.deactivate'),
         danger: !activating,
         onConfirm: submitEdit,
       })
@@ -115,11 +117,11 @@ export default function UsersPage() {
   const handleToggleActive = (u: User) => {
     const activating = !u.is_active
     setPendingConfirm({
-      title: activating ? 'Activate user' : 'Deactivate user',
+      title: activating ? t('users.activateTitle') : t('users.deactivateTitle'),
       message: activating
-        ? `Activate user "${u.username}"? They will be able to sign in again.`
-        : `Deactivate user "${u.username}"? They will no longer be able to sign in.`,
-      confirmLabel: activating ? 'Activate' : 'Deactivate',
+        ? t('users.activateMessage', { username: u.username })
+        : t('users.deactivateMessage', { username: u.username }),
+      confirmLabel: activating ? t('users.activate') : t('users.deactivate'),
       danger: !activating,
       onConfirm: async () => {
         await api.updateUser(u.id, { is_active: !u.is_active })
@@ -130,9 +132,12 @@ export default function UsersPage() {
 
   const handleDelete = (u: User) => {
     setPendingConfirm({
-      title: 'Delete user',
-      message: `Delete user "${u.username}"? This action cannot be undone.`,
-      confirmLabel: 'Delete',
+      title: t('users.deleteTitle'),
+      message: t('users.deleteMessage', {
+        username: u.username,
+        cannotUndo: t('common.cannotUndo'),
+      }),
+      confirmLabel: t('common.delete'),
       danger: true,
       onConfirm: async () => {
         await api.deleteUser(u.id)
@@ -148,7 +153,7 @@ export default function UsersPage() {
     try {
       await action()
     } catch (err) {
-      alert(err instanceof Error ? err.message : 'Action failed')
+      alert(err instanceof Error ? err.message : t('errors.actionFailed'))
     }
   }
 
@@ -169,9 +174,9 @@ export default function UsersPage() {
       />
 
       <div className="page-header">
-        <h1>User Management</h1>
+        <h1>{t('users.title')}</h1>
         <button className="btn btn-primary" onClick={() => setShowForm(!showForm)}>
-          {showForm ? 'Cancel' : '+ Add User'}
+          {showForm ? t('common.cancel') : t('users.addUser')}
         </button>
       </div>
 
@@ -179,10 +184,10 @@ export default function UsersPage() {
 
       {showForm && (
         <div className="card" style={{ marginBottom: 24, maxWidth: 480 }}>
-          <h2 style={{ marginTop: 0 }}>Create User</h2>
+          <h2 style={{ marginTop: 0 }}>{t('users.createUser')}</h2>
           <form onSubmit={handleCreate}>
             <div className="form-group">
-              <label>Email</label>
+              <label>{t('common.email')}</label>
               <input
                 type="email"
                 value={form.email}
@@ -191,7 +196,7 @@ export default function UsersPage() {
               />
             </div>
             <div className="form-group">
-              <label>Username</label>
+              <label>{t('common.username')}</label>
               <input
                 value={form.username}
                 onChange={(e) => setForm({ ...form, username: e.target.value })}
@@ -200,7 +205,7 @@ export default function UsersPage() {
               />
             </div>
             <div className="form-group">
-              <label>Password</label>
+              <label>{t('common.password')}</label>
               <input
                 type="password"
                 value={form.password}
@@ -210,26 +215,28 @@ export default function UsersPage() {
               />
             </div>
             <div className="form-group">
-              <label>Role</label>
+              <label>{t('common.role')}</label>
               <select
                 value={form.role}
                 onChange={(e) => setForm({ ...form, role: e.target.value as 'user' | 'admin' })}
               >
-                <option value="user">User</option>
-                <option value="admin">Admin</option>
+                <option value="user">{t('roles.user')}</option>
+                <option value="admin">{t('roles.admin')}</option>
               </select>
             </div>
-            <button type="submit" className="btn btn-primary">Create</button>
+            <button type="submit" className="btn btn-primary">{t('common.create')}</button>
           </form>
         </div>
       )}
 
       {editingUser && (
         <div className="card" style={{ marginBottom: 24, maxWidth: 480 }}>
-          <h2 style={{ marginTop: 0 }}>Edit User: {editingUser.username}</h2>
+          <h2 style={{ marginTop: 0 }}>
+            {t('users.editUser', { username: editingUser.username })}
+          </h2>
           <form onSubmit={handleEdit}>
             <div className="form-group">
-              <label>Email</label>
+              <label>{t('common.email')}</label>
               <input
                 type="email"
                 value={editForm.email}
@@ -238,7 +245,7 @@ export default function UsersPage() {
               />
             </div>
             <div className="form-group">
-              <label>Username</label>
+              <label>{t('common.username')}</label>
               <input
                 value={editForm.username}
                 onChange={(e) => setEditForm({ ...editForm, username: e.target.value })}
@@ -247,7 +254,7 @@ export default function UsersPage() {
               />
             </div>
             <div className="form-group">
-              <label>New Password (leave empty to keep)</label>
+              <label>{t('users.newPasswordHint')}</label>
               <input
                 type="password"
                 value={editForm.password}
@@ -256,7 +263,7 @@ export default function UsersPage() {
               />
             </div>
             <div className="form-group">
-              <label>Role</label>
+              <label>{t('common.role')}</label>
               <select
                 value={editForm.role}
                 onChange={(e) =>
@@ -264,8 +271,8 @@ export default function UsersPage() {
                 }
                 disabled={editingUser.id === currentUser?.id}
               >
-                <option value="user">User</option>
-                <option value="admin">Admin</option>
+                <option value="user">{t('roles.user')}</option>
+                <option value="admin">{t('roles.admin')}</option>
               </select>
             </div>
             <div className="form-group">
@@ -279,17 +286,17 @@ export default function UsersPage() {
                   disabled={editingUser.id === currentUser?.id}
                   style={{ width: 'auto', marginRight: 8 }}
                 />
-                Active
+                {t('common.active')}
               </label>
             </div>
             <div style={{ display: 'flex', gap: 8 }}>
-              <button type="submit" className="btn btn-primary">Save</button>
+              <button type="submit" className="btn btn-primary">{t('common.save')}</button>
               <button
                 type="button"
                 className="btn btn-secondary"
                 onClick={() => setEditingUser(null)}
               >
-                Cancel
+                {t('common.cancel')}
               </button>
             </div>
           </form>
@@ -297,18 +304,18 @@ export default function UsersPage() {
       )}
 
       {loading ? (
-        <p>Loading...</p>
+        <p>{t('common.loading')}</p>
       ) : (
         <div className="card">
           <table className="table">
             <thead>
               <tr>
-                <th>Username</th>
-                <th>Email</th>
-                <th>Role</th>
-                <th>Status</th>
-                <th>Created</th>
-                <th>Actions</th>
+                <th>{t('common.username')}</th>
+                <th>{t('common.email')}</th>
+                <th>{t('common.role')}</th>
+                <th>{t('users.status')}</th>
+                <th>{t('common.created')}</th>
+                <th>{t('common.actions')}</th>
               </tr>
             </thead>
             <tbody>
@@ -317,11 +324,11 @@ export default function UsersPage() {
                   <td>
                     <strong>{u.username}</strong>
                     {u.id === currentUser?.id && (
-                      <span className="style-hint"> (you)</span>
+                      <span className="style-hint"> {t('common.you')}</span>
                     )}
                   </td>
                   <td>{u.email}</td>
-                  <td>{u.role}</td>
+                  <td>{t(`roles.${u.role}`)}</td>
                   <td>
                     <span
                       className={`badge badge-${u.is_active ? 'user' : 'admin'}`}
@@ -331,30 +338,30 @@ export default function UsersPage() {
                           : { background: '#fee2e2', color: '#dc2626' }
                       }
                     >
-                      {u.is_active ? 'active' : 'inactive'}
+                      {u.is_active ? t('status.active') : t('status.inactive')}
                     </span>
                   </td>
-                  <td>{new Date(u.created_at).toLocaleDateString()}</td>
+                  <td>{formatDate(u.created_at)}</td>
                   <td style={{ display: 'flex', gap: 8, flexWrap: 'wrap' }}>
                     <button
                       className="btn btn-primary btn-sm"
                       onClick={() => openEdit(u)}
                     >
-                      Edit
+                      {t('common.edit')}
                     </button>
                     <button
                       className="btn btn-secondary btn-sm"
                       onClick={() => handleToggleActive(u)}
                       disabled={u.id === currentUser?.id}
                     >
-                      {u.is_active ? 'Deactivate' : 'Activate'}
+                      {u.is_active ? t('users.deactivate') : t('users.activate')}
                     </button>
                     <button
                       className="btn btn-danger btn-sm"
                       onClick={() => handleDelete(u)}
                       disabled={u.id === currentUser?.id}
                     >
-                      Delete
+                      {t('common.delete')}
                     </button>
                   </td>
                 </tr>
diff --git a/frontend/tsconfig.tsbuildinfo b/frontend/tsconfig.tsbuildinfo
index 4414d40..a4efda7 100644
--- a/frontend/tsconfig.tsbuildinfo
+++ b/frontend/tsconfig.tsbuildinfo
@@ -1 +1 @@
-{"root":["./src/App.tsx","./src/api.ts","./src/main.tsx","./src/types.ts","./src/vite-env.d.ts","./src/components/ConfirmDialog.tsx","./src/components/Navbar.tsx","./src/components/TableRowEditor.tsx","./src/components/VariableField.tsx","./src/context/AuthContext.tsx","./src/pages/ActivatePage.tsx","./src/pages/CreateTemplatePage.tsx","./src/pages/DocumentDetailPage.tsx","./src/pages/DocumentsPage.tsx","./src/pages/EditDocumentPage.tsx","./src/pages/FillTemplatePage.tsx","./src/pages/ForgotPasswordPage.tsx","./src/pages/LoginPage.tsx","./src/pages/LogsPage.tsx","./src/pages/RegisterPage.tsx","./src/pages/ResetPasswordPage.tsx","./src/pages/TemplateDetailPage.tsx","./src/pages/TemplatesPage.tsx","./src/pages/UsersPage.tsx"],"version":"5.9.3"}
\ No newline at end of file
+{"root":["./src/App.tsx","./src/api.ts","./src/main.tsx","./src/types.ts","./src/vite-env.d.ts","./src/components/AuthShell.tsx","./src/components/ConfirmDialog.tsx","./src/components/LanguageSwitcher.tsx","./src/components/Navbar.tsx","./src/components/TableRowEditor.tsx","./src/components/VariableField.tsx","./src/context/AuthContext.tsx","./src/context/I18nContext.tsx","./src/i18n/index.ts","./src/i18n/locales/en.ts","./src/i18n/locales/ru.ts","./src/pages/ActivatePage.tsx","./src/pages/CreateTemplatePage.tsx","./src/pages/DocumentDetailPage.tsx","./src/pages/DocumentsPage.tsx","./src/pages/EditDocumentPage.tsx","./src/pages/FillTemplatePage.tsx","./src/pages/ForgotPasswordPage.tsx","./src/pages/LoginPage.tsx","./src/pages/LogsPage.tsx","./src/pages/RegisterPage.tsx","./src/pages/ResetPasswordPage.tsx","./src/pages/TemplateDetailPage.tsx","./src/pages/TemplatesPage.tsx","./src/pages/UsersPage.tsx"],"version":"5.9.3"}
\ No newline at end of file