From 63860c94af05f91b6a0dea6f60188257ef1ad27d Mon Sep 17 00:00:00 2001
From: miteruzo <miteruzo@naver.com>
Date: Sun, 18 Oct 2026 00:07:07 +0900
Subject: [PATCH] #428

---
 frontend/src/components/SortHeader.tsx        |   4 +-
 frontend/src/components/TagLink.tsx           |  14 ++-
 frontend/src/components/TranslatedText.tsx    |  13 +-
 frontend/src/components/common/Pagination.tsx |  18 ++-
 frontend/src/lib/i18n.ts                      |  42 ++++++-
 frontend/src/lib/useUITranslation.ts          |  16 +++
 frontend/src/lib/utils.ts                     |  20 +++
 frontend/src/locales/ain-Kana/common.json     |  38 ++++++
 frontend/src/locales/ain-Kana/tags.json       |  17 +++
 frontend/src/locales/ja/common.json           |  33 +++++
 frontend/src/locales/ja/tags.json             |  13 ++
 frontend/src/pages/tags/TagListPage.tsx       | 118 +++++++++++-------
 12 files changed, 280 insertions(+), 66 deletions(-)
 create mode 100644 frontend/src/lib/useUITranslation.ts
 create mode 100644 frontend/src/locales/ain-Kana/common.json
 create mode 100644 frontend/src/locales/ain-Kana/tags.json
 create mode 100644 frontend/src/locales/ja/common.json
 create mode 100644 frontend/src/locales/ja/tags.json

diff --git a/frontend/src/components/SortHeader.tsx b/frontend/src/components/SortHeader.tsx
index 35239af..2a9bf3f 100644
--- a/frontend/src/components/SortHeader.tsx
+++ b/frontend/src/components/SortHeader.tsx
@@ -2,10 +2,12 @@ import { useLocation } from 'react-router-dom'
 
 import PrefetchLink from '@/components/PrefetchLink'
 
+import type { ReactNode } from 'react'
+
 
 export default <T extends string,>({ by, label, currentOrder, defaultDirection }: {
     by:               T
-    label:            string
+    label:            ReactNode
     currentOrder:     `${ T }:${ 'asc' | 'desc' }`
     defaultDirection: Record<T, 'asc' | 'desc'> }) => {
   const [fld, dir] = currentOrder.split (':')
diff --git a/frontend/src/components/TagLink.tsx b/frontend/src/components/TagLink.tsx
index 04328c2..cded9f3 100644
--- a/frontend/src/components/TagLink.tsx
+++ b/frontend/src/components/TagLink.tsx
@@ -1,5 +1,6 @@
 import PrefetchLink from '@/components/PrefetchLink'
 import ResponsiveMarqueeText from '@/components/ResponsiveMarqueeText'
+import { useUITranslation } from '@/lib/useUITranslation'
 import { cn } from '@/lib/utils'
 
 import type { ComponentProps, CSSProperties, FC, HTMLAttributes } from 'react'
@@ -67,6 +68,10 @@ const TagLink: FC<Props> = ({ tag,
 			      style,
 			      title,
 			      ...props }) => {
+  const { message } = useUITranslation ()
+  const missingMaterial = message ('tagLink.missingMaterial', { name: tag.name })
+  const missingDeerjikist = message ('tagLink.missingDeerjikist', { name: tag.name })
+  const missingWiki = message ('tagLink.missingWiki', { name: tag.name })
   const colourStyle = {
       '--tag-link-colour': `var(--tag-colour-${ tag.category })`,
       '--tag-link-hover-colour': `var(--tag-colour-${ tag.category }-hover)`,
@@ -121,7 +126,8 @@ const TagLink: FC<Props> = ({ tag,
 			  to={`/materials/new?tag=${ encodeURIComponent (tag.name) }`}
 			  className="animate-[wiki-blink_.25s_steps(2,end)_infinite]
 				     dark:animate-[wiki-blink-dark_.25s_steps(2,end)_infinite]"
-			  title={`${ tag.name } 素材情報が存在しません．`}>
+			  lang={missingMaterial.language}
+			  title={missingMaterial.text}>
 			!
 		      </PrefetchLink>)
 		  : (
@@ -131,7 +137,8 @@ const TagLink: FC<Props> = ({ tag,
 			      to={`/tags/${ tag.id }/deerjikists`}
 			      className="animate-[wiki-blink_.25s_steps(2,end)_infinite]
 					 dark:animate-[wiki-blink-dark_.25s_steps(2,end)_infinite]"
-			      title={`${ tag.name } に関する情報が存在しません．`}>
+			      lang={missingDeerjikist.language}
+			      title={missingDeerjikist.text}>
 			    !
 			  </PrefetchLink>)
 		      : (
@@ -139,7 +146,8 @@ const TagLink: FC<Props> = ({ tag,
 			      to={`/wiki/${ encodeURIComponent (tag.name) }`}
 			      className="animate-[wiki-blink_.25s_steps(2,end)_infinite]
 					 dark:animate-[wiki-blink-dark_.25s_steps(2,end)_infinite]"
-			      title={`${ tag.name } Wiki が存在しません．`}>
+			      lang={missingWiki.language}
+			      title={missingWiki.text}>
 			    !
 			  </PrefetchLink>)))}
 	    </span>)}
diff --git a/frontend/src/components/TranslatedText.tsx b/frontend/src/components/TranslatedText.tsx
index 1b1303e..2942c04 100644
--- a/frontend/src/components/TranslatedText.tsx
+++ b/frontend/src/components/TranslatedText.tsx
@@ -1,7 +1,5 @@
-import { useTranslation } from 'react-i18next'
-
 import LocalisedText from '@/components/LocalisedText'
-import { useLocale } from '@/lib/useLocale'
+import { useUITranslation } from '@/lib/useUITranslation'
 
 type Props = {
     messageKey: string
@@ -13,12 +11,11 @@ type Props = {
 const TranslatedText = (
     { messageKey, namespace = 'navigation', values, className }: Props,
 ) => {
-  const locale = useLocale ()
-  const { t } = useTranslation (namespace, { lng: locale })
-  const result = t (messageKey, { ...values, returnDetails: true })
+  const { message } = useUITranslation (namespace)
+  const result = message (messageKey, values)
   return (
-      <LocalisedText language={result.usedLng} className={className}>
-	{result.res}
+      <LocalisedText language={result.language} className={className}>
+	{result.text}
       </LocalisedText>)
 }
 
diff --git a/frontend/src/components/common/Pagination.tsx b/frontend/src/components/common/Pagination.tsx
index 763b77c..47c54e1 100644
--- a/frontend/src/components/common/Pagination.tsx
+++ b/frontend/src/components/common/Pagination.tsx
@@ -1,6 +1,7 @@
 import { useLocation } from 'react-router-dom'
 
 import PrefetchLink from '@/components/PrefetchLink'
+import { useUITranslation } from '@/lib/useUITranslation'
 
 import type { FC } from 'react'
 
@@ -49,6 +50,7 @@ const getPages = (
 
 const Pagination: FC<Props> = ({ page, totalPages, siblingCount = 3 }) => {
   const location = useLocation ()
+  const { message } = useUITranslation ()
 
   const buildTo = (p: number) => {
     const qs = new URLSearchParams (location.search)
@@ -59,7 +61,9 @@ const Pagination: FC<Props> = ({ page, totalPages, siblingCount = 3 }) => {
   const pages = getPages (page, totalPages, siblingCount)
 
   return (
-      <nav className="mt-4 flex justify-center" aria-label="Pagination">
+      <nav className="mt-4 flex justify-center"
+	  lang={message ('pagination.label').language}
+	  aria-label={message ('pagination.label').text}>
 	<div className="flex items-center gap-2">
 	  {(page > 1)
 	   ? (
@@ -67,13 +71,15 @@ const Pagination: FC<Props> = ({ page, totalPages, siblingCount = 3 }) => {
 		<PrefetchLink
 		    className="md:hidden p-2"
 		    to={buildTo (1)}
-		    aria-label="最初のページ">
+		    lang={message ('pagination.first').language}
+		    aria-label={message ('pagination.first').text}>
 		  |&lt;
 		</PrefetchLink>
 		<PrefetchLink
 		    className="p-2"
 		    to={buildTo (page - 1)}
-		    aria-label="前のページ">
+		    lang={message ('pagination.previous').language}
+		    aria-label={message ('pagination.previous').text}>
 		  &lt;
 		</PrefetchLink>
 	      </>)
@@ -106,13 +112,15 @@ const Pagination: FC<Props> = ({ page, totalPages, siblingCount = 3 }) => {
 		<PrefetchLink
 		    className="p-2"
 		    to={buildTo (page + 1)}
-		    aria-label="次のページ">
+		    lang={message ('pagination.next').language}
+		    aria-label={message ('pagination.next').text}>
 		  &gt;
 		</PrefetchLink>
 		<PrefetchLink
 		    className="md:hidden p-2"
 		    to={buildTo (totalPages)}
-		    aria-label="最後のページ">
+		    lang={message ('pagination.last').language}
+		    aria-label={message ('pagination.last').text}>
 		  &gt;|
 		</PrefetchLink>
 	      </>)
diff --git a/frontend/src/lib/i18n.ts b/frontend/src/lib/i18n.ts
index e9ff4f2..b0332c8 100644
--- a/frontend/src/lib/i18n.ts
+++ b/frontend/src/lib/i18n.ts
@@ -2,12 +2,36 @@ import { createInstance } from 'i18next'
 import { initReactI18next } from 'react-i18next'
 
 import ainuNavigation from '@/locales/ain-Kana/navigation.json'
+import ainuCommon from '@/locales/ain-Kana/common.json'
+import ainuTags from '@/locales/ain-Kana/tags.json'
 import nipponeseNavigation from '@/locales/ja/navigation.json'
+import nipponeseCommon from '@/locales/ja/common.json'
+import nipponeseTags from '@/locales/ja/tags.json'
 
 import type { LocaleCode } from '@/lib/locales'
 
 export const i18n = createInstance ()
 
+
+// Keep Japanese placeholders editable without reporting them as completed translations.
+const translatedResource = (resource: Record<string, unknown>): Record<string, unknown> => {
+  const untranslated = new Set (
+      Array.isArray (resource._untranslated) ? resource._untranslated : [])
+  const select = (entries: Record<string, unknown>, prefix = ''): Record<string, unknown> =>
+      Object.fromEntries (Object.entries (entries).flatMap (([key, value]) => {
+	const path = prefix ? `${ prefix }.${ key }` : key
+	if (key === '_untranslated' || untranslated.has (path))
+	  return []
+	const translated =
+	    (value != null && typeof value === 'object' && !(Array.isArray (value)))
+	    ? select (value as Record<string, unknown>, path)
+	    : value
+	return [[key, translated]]
+      }))
+  return select (resource)
+}
+
+
 void i18n.use (initReactI18next).init ({
     lng: 'ja',
     fallbackLng: 'ja',
@@ -15,10 +39,13 @@ void i18n.use (initReactI18next).init ({
     load: 'currentOnly',
     initAsync: false,
     defaultNS: 'navigation',
-    ns: ['navigation'],
+    ns: ['navigation', 'common', 'tags'],
     resources: {
-	ja: { navigation: nipponeseNavigation },
-	'ain-Kana': { navigation: ainuNavigation } },
+	ja: { navigation: nipponeseNavigation, common: nipponeseCommon, tags: nipponeseTags },
+	'ain-Kana': {
+	    navigation: ainuNavigation,
+	    common: translatedResource (ainuCommon),
+	    tags: translatedResource (ainuTags) } },
     interpolation: { escapeValue: false },
     returnNull: false,
     returnEmptyString: false,
@@ -50,7 +77,10 @@ export const untranslatedKeys = (
 
 if (import.meta.env.DEV)
 {
-  const missing = untranslatedKeys ('ain-Kana')
-  if (missing.length > 0)
-    console.warn ('[i18n] ain-Kana: untranslated navigation keys', missing)
+  for (const namespace of ['navigation', 'common', 'tags'])
+  {
+    const missing = untranslatedKeys ('ain-Kana', namespace)
+    if (missing.length > 0)
+      console.warn (`[i18n] ain-Kana: untranslated ${ namespace } keys`, missing)
+  }
 }
diff --git a/frontend/src/lib/useUITranslation.ts b/frontend/src/lib/useUITranslation.ts
new file mode 100644
index 0000000..f90180b
--- /dev/null
+++ b/frontend/src/lib/useUITranslation.ts
@@ -0,0 +1,16 @@
+import { useTranslation } from 'react-i18next'
+
+import { useLocale } from '@/lib/useLocale'
+
+
+export const useUITranslation = (namespace = 'common') => {
+  const locale = useLocale ()
+  const { t } = useTranslation (namespace, { lng: locale })
+
+  const message = (key: string, values?: Record<string, string | number>) => {
+    const result = t (key, { ...values, returnDetails: true })
+    return { text: result.res, language: result.usedLng }
+  }
+
+  return { message }
+}
diff --git a/frontend/src/lib/utils.ts b/frontend/src/lib/utils.ts
index b758652..23c5999 100644
--- a/frontend/src/lib/utils.ts
+++ b/frontend/src/lib/utils.ts
@@ -3,6 +3,8 @@ import { twMerge } from 'tailwind-merge'
 
 import type { ClassValue } from 'clsx'
 
+import type { LocaleCode } from '@/lib/locales'
+
 
 export const toDate = (d: string | Date): Date => typeof d === 'string' ? new Date (d) : d
 
@@ -25,6 +27,24 @@ export const dateString = (
 	  second: unknown == null ? 'numeric' : undefined })
 
 
+export const localisedDateString = (value: string | Date, locale: LocaleCode): string => {
+  if (locale === 'ja')
+    return dateString (value)
+
+  const date = toDate (value)
+  if (Number.isNaN (date.getTime ()))
+    return dateString (value)
+
+  const parts = new Intl.DateTimeFormat ('en-CA', {
+      year: 'numeric', month: '2-digit', day: '2-digit',
+      hour: '2-digit', minute: '2-digit', second: '2-digit',
+      hourCycle: 'h23' }).formatToParts (date)
+  const part = (type: string) => parts.find (entry => entry.type === type)?.value ?? ''
+  return `${ part ('year') }-${ part ('month') }-${ part ('day') }\u3000${
+      part ('hour') }:${ part ('minute') }:${ part ('second') }`
+}
+
+
 export const originalCreatedAtString = (
     f:  string | Date | null,
     b:  string | Date | null): string => {
diff --git a/frontend/src/locales/ain-Kana/common.json b/frontend/src/locales/ain-Kana/common.json
new file mode 100644
index 0000000..74db178
--- /dev/null
+++ b/frontend/src/locales/ain-Kana/common.json
@@ -0,0 +1,38 @@
+{
+  "_untranslated": [
+    "countLabel", "categoryLabel", "stateLabel", "loading", "fetchError",
+    "states", "categories.deerjikist", "categories.meme", "categories.character",
+    "categories.general", "categories.meta", "categories.nico", "pagination", "tagLink"
+  ],
+  "countLabel": "件数",
+  "categoryLabel": "カテゴリ",
+  "stateLabel": "状態",
+  "search": "イフナラ",
+  "loading": "Loading...",
+  "fetchError": "データ取得エラー",
+  "states": {
+    "active": "有効",
+    "deprecated": "廃止"
+  },
+  "categories": {
+    "deerjikist": "ニジラー",
+    "meme": "原作・ネタ元・ミーム等",
+    "character": "キャラクター",
+    "general": "一般",
+    "material": "チカㇻペ",
+    "meta": "メタタグ",
+    "nico": "ニコニコタグ"
+  },
+  "pagination": {
+    "label": "Pagination",
+    "first": "最初のページ",
+    "previous": "前のページ",
+    "next": "次のページ",
+    "last": "最後のページ"
+  },
+  "tagLink": {
+    "missingMaterial": "{{name}} 素材情報が存在しません．",
+    "missingDeerjikist": "{{name}} に関する情報が存在しません．",
+    "missingWiki": "{{name}} Wiki が存在しません．"
+  }
+}
diff --git a/frontend/src/locales/ain-Kana/tags.json b/frontend/src/locales/ain-Kana/tags.json
new file mode 100644
index 0000000..407a016
--- /dev/null
+++ b/frontend/src/locales/ain-Kana/tags.json
@@ -0,0 +1,17 @@
+{
+  "_untranslated": [
+    "name", "postCount", "firstRecordedAt", "definitionUpdatedAt", "aliases",
+    "parents", "firstRecordedColumn", "updatedAt", "empty"
+  ],
+  "title": "タㇰ",
+  "name": "名前",
+  "postCount": "広場の投稿数",
+  "firstRecordedAt": "はじめて記載された日時",
+  "definitionUpdatedAt": "定義の更新日時",
+  "aliases": "別名",
+  "parents": "上位タグ",
+  "firstRecordedColumn": "最初の記載日時",
+  "updatedAt": "更新日時",
+  "history": "フㇱコアンペ",
+  "empty": "結果ないよ（笑）"
+}
diff --git a/frontend/src/locales/ja/common.json b/frontend/src/locales/ja/common.json
new file mode 100644
index 0000000..c8669f9
--- /dev/null
+++ b/frontend/src/locales/ja/common.json
@@ -0,0 +1,33 @@
+{
+  "countLabel": "件数",
+  "categoryLabel": "カテゴリ",
+  "stateLabel": "状態",
+  "search": "検索",
+  "loading": "Loading...",
+  "fetchError": "データ取得エラー",
+  "states": {
+    "active": "有効",
+    "deprecated": "廃止"
+  },
+  "categories": {
+    "deerjikist": "ニジラー",
+    "meme": "原作・ネタ元・ミーム等",
+    "character": "キャラクター",
+    "general": "一般",
+    "material": "素材",
+    "meta": "メタタグ",
+    "nico": "ニコニコタグ"
+  },
+  "pagination": {
+    "label": "Pagination",
+    "first": "最初のページ",
+    "previous": "前のページ",
+    "next": "次のページ",
+    "last": "最後のページ"
+  },
+  "tagLink": {
+    "missingMaterial": "{{name}} 素材情報が存在しません．",
+    "missingDeerjikist": "{{name}} に関する情報が存在しません．",
+    "missingWiki": "{{name}} Wiki が存在しません．"
+  }
+}
diff --git a/frontend/src/locales/ja/tags.json b/frontend/src/locales/ja/tags.json
new file mode 100644
index 0000000..6e880da
--- /dev/null
+++ b/frontend/src/locales/ja/tags.json
@@ -0,0 +1,13 @@
+{
+  "title": "タグ",
+  "name": "名前",
+  "postCount": "広場の投稿数",
+  "firstRecordedAt": "はじめて記載された日時",
+  "definitionUpdatedAt": "定義の更新日時",
+  "aliases": "別名",
+  "parents": "上位タグ",
+  "firstRecordedColumn": "最初の記載日時",
+  "updatedAt": "更新日時",
+  "history": "耕作履歴",
+  "empty": "結果ないよ（笑）"
+}
diff --git a/frontend/src/pages/tags/TagListPage.tsx b/frontend/src/pages/tags/TagListPage.tsx
index ad34248..5f160b3 100644
--- a/frontend/src/pages/tags/TagListPage.tsx
+++ b/frontend/src/pages/tags/TagListPage.tsx
@@ -4,16 +4,18 @@ import { Helmet } from 'react-helmet-async'
 import { useLocation } from 'react-router-dom'
 
 import { useLocale, useLocaleNavigate } from '@/lib/useLocale'
+import LocalisedText from '@/components/LocalisedText'
 import PrefetchLink from '@/components/PrefetchLink'
 import SortHeader from '@/components/SortHeader'
 import TagLink from '@/components/TagLink'
+import TranslatedText from '@/components/TranslatedText'
 import DateTimeField from '@/components/common/DateTimeField'
 import FormField from '@/components/common/FormField'
 import PageTitle from '@/components/common/PageTitle'
 import Pagination from '@/components/common/Pagination'
 import MainArea from '@/components/layout/MainArea'
 import { SITE_TITLE } from '@/config'
-import { CATEGORIES, CATEGORY_NAMES } from '@/consts'
+import { CATEGORIES } from '@/consts'
 import { clientScrollBehaviour } from '@/lib/clientAnimation'
 import { tagsKeys } from '@/lib/queryKeys'
 import {
@@ -26,8 +28,9 @@ import {
 } from '@/lib/settings'
 import { useClientBehaviourSettings } from '@/lib/useClientBehaviourSettings'
 import { useKeyboardShortcuts } from '@/lib/useKeyboardShortcuts'
+import { useUITranslation } from '@/lib/useUITranslation'
 import { fetchTags } from '@/lib/tags'
-import { dateString, inputClass } from '@/lib/utils'
+import { inputClass, localisedDateString } from '@/lib/utils'
 
 import type { FC, FormEvent } from 'react'
 
@@ -45,8 +48,6 @@ const boolFromQuery = (value: string | null): boolean =>
     ['1', 'true', 'on', 'yes', ''].includes ((value ?? '').toLowerCase ())
 
 
-const tagStateLabel = (deprecatedAt: string | null) => deprecatedAt ? '廃止' : ''
-
 const parseLimit = (value: string | null): 20 | 50 | 100 | null => {
   const n = Number (value)
   return n === 20 || n === 50 || n === 100 ? n : null
@@ -75,6 +76,8 @@ const parseOrder = (value: string | null): FetchTagsOrder | null => {
 
 const TagListPage: FC = () => {
   const locale = useLocale ()
+  const { message } = useUITranslation ('tags')
+  const label = (key: string) => <TranslatedText namespace="tags" messageKey={key}/>
   const behaviourSettings = useClientBehaviourSettings ()
   const animationMode = behaviourSettings.animation ?? 'normal'
   const location = useLocation ()
@@ -99,7 +102,8 @@ const TagListPage: FC = () => {
   const qCreatedTo = query.get ('created_to') ?? ''
   const qUpdatedFrom = query.get ('updated_from') ?? ''
   const qUpdatedTo = query.get ('updated_to') ?? ''
-  const qDeprecated = query.has ('deprecated')
+  const qDeprecated =
+      query.has ('deprecated')
       ? boolFromQuery (query.get ('deprecated'))
       : null
   const order = (
@@ -130,7 +134,7 @@ const TagListPage: FC = () => {
       updatedFrom: qUpdatedFrom,
       updatedTo: qUpdatedTo,
       deprecated: qDeprecated }
-  const { data, isLoading: loading } = useQuery ({
+  const { data, isLoading: loading, isError } = useQuery ({
       queryKey: tagsKeys.index (keys, locale),
       queryFn: () => fetchTags (keys, locale) })
   const results = data?.tags ?? []
@@ -203,32 +207,28 @@ const TagListPage: FC = () => {
 
   useKeyboardShortcuts (useMemo (() => ({
       ...(page > 1
-	  ? {
-	      'pagination.previous': () => {
+	  ? { 'pagination.previous': () => {
 		  updatePage (page - 1)
-	      },
-	  }
+	      } }
 	  : { }),
       ...(totalPages > 0 && page < totalPages
-	  ? {
-	      'pagination.next': () => {
+	  ? { 'pagination.next': () => {
 		  updatePage (Math.min (page + 1, totalPages))
-	      },
-	  }
+	      } }
 	  : { }),
   }), [page, totalPages, location.search]))
 
   return (
       <MainArea>
 	<Helmet>
-	  <title>タグ | {SITE_TITLE}</title>
+	  <title>{message ('title').text} | {SITE_TITLE}</title>
 	</Helmet>
 
 	<div className="max-w-xl">
 	  <div className="flex flex-wrap items-center justify-between gap-3">
-	    <PageTitle>タグ</PageTitle>
+	    <PageTitle>{label ('title')}</PageTitle>
 	    <label className="flex items-center gap-2 text-xs text-muted-foreground">
-	      <span>件数</span>
+	      <span>{label ('common:countLabel')}</span>
 	      <select
 		  value={limit}
 		  onChange={ev => updateListQuery ({
@@ -246,7 +246,7 @@ const TagListPage: FC = () => {
 
 	  <form onSubmit={handleSearch} className="space-y-2">
 	    {/* 名前 */}
-	    <FormField label="名前">
+	    <FormField label={label ('name')}>
 	      {({ invalid }) => (
 		  <input
 		      type="text"
@@ -257,7 +257,7 @@ const TagListPage: FC = () => {
 	    </FormField>
 
 	    {/* カテゴリ */}
-	    <FormField label="カテゴリ">
+	    <FormField label={label ('common:categoryLabel')}>
 	      {({ invalid }) => (
 		  <select
 		      value={category ?? ''}
@@ -265,14 +265,15 @@ const TagListPage: FC = () => {
 		      className={inputClass (invalid)}>
 		    <option value="">&nbsp;</option>
 		    {CATEGORIES.map (cat => (
-			<option key={cat} value={cat}>
-			  {CATEGORY_NAMES[cat]}
+			<option key={cat} value={cat}
+			    lang={message (`common:categories.${ cat }`).language}>
+			  {message (`common:categories.${ cat }`).text}
 			</option>))}
 		  </select>)}
 	    </FormField>
 
 	    {/* 広場の投稿数 */}
-	    <FormField label="広場の投稿数">
+	    <FormField label={label ('postCount')}>
 	      {({ invalid }) => (
 		  <>
 		    <input
@@ -294,34 +295,38 @@ const TagListPage: FC = () => {
 	    </FormField>
 
 	    {/* はじめて記載された日時 */}
-	    <FormField label="はじめて記載された日時">
+	    <FormField label={label ('firstRecordedAt')}>
 	      {() => (
 		  <>
 		    <DateTimeField
+			lang={locale}
 			value={createdFrom ?? undefined}
 			onChange={setCreatedFrom}/>
 		    <span className="mx-1">〜</span>
 		    <DateTimeField
+			lang={locale}
 			value={createdTo ?? undefined}
 			onChange={setCreatedTo}/>
 		  </>)}
 	    </FormField>
 
 	    {/* 定義の更新日時 */}
-	    <FormField label="定義の更新日時">
+	    <FormField label={label ('definitionUpdatedAt')}>
 	      {() => (
 		  <>
 		    <DateTimeField
+			lang={locale}
 			value={updatedFrom ?? undefined}
 			onChange={setUpdatedFrom}/>
 		    <span className="mx-1">〜</span>
 		    <DateTimeField
+			lang={locale}
 			value={updatedTo ?? undefined}
 			onChange={setUpdatedTo}/>
 		  </>)}
 	    </FormField>
 
-	    <FormField label="状態">
+	    <FormField label={label ('common:stateLabel')}>
 	      {({ invalid }) => (
 		  <select
 		      value={deprecated == null ? '' : (deprecated ? '1' : '0')}
@@ -331,8 +336,12 @@ const TagListPage: FC = () => {
 			  : e.target.value === '1')}
 		      className={inputClass (invalid)}>
 		    <option value="">&nbsp;</option>
-		    <option value="0">有効</option>
-		    <option value="1">廃止</option>
+		    <option value="0" lang={message ('common:states.active').language}>
+		      {message ('common:states.active').text}
+		    </option>
+		    <option value="1" lang={message ('common:states.deprecated').language}>
+		      {message ('common:states.deprecated').text}
+		    </option>
 		  </select>)}
 	    </FormField>
 
@@ -340,13 +349,14 @@ const TagListPage: FC = () => {
 	      <button
 		  type="submit"
 		  className="bg-blue-500 text-white px-4 py-2 rounded">
-		検索
+		{label ('common:search')}
 	      </button>
 	    </div>
 	  </form>
 	</div>
 
-	{loading ? 'Loading...' : (results.length > 0 ? (
+	{isError && <p role="alert">{label ('common:fetchError')}</p>}
+	{loading ? label ('common:loading') : (results.length > 0 ? (
 	    <div className="mt-4">
 	      <div className="overflow-x-auto">
 		<table className="w-full min-w-[2000px] table-fixed border-collapse">
@@ -367,38 +377,44 @@ const TagListPage: FC = () => {
 		      <th className="p-2 text-left whitespace-nowrap">
 			<SortHeader<FetchTagsOrderField>
 			    by="name"
-			    label="タグ"
+			    label={label ('title')}
 			    currentOrder={order}
 			    defaultDirection={defaultDirection}/>
 		      </th>
 		      <th className="p-2 text-left whitespace-nowrap">
 			<SortHeader<FetchTagsOrderField>
 			    by="post_count"
-			    label="件数"
+			    label={label ('common:countLabel')}
 			    currentOrder={order}
 			    defaultDirection={defaultDirection}/>
 		      </th>
 		      <th className="p-2 text-left whitespace-nowrap">
 			<SortHeader<FetchTagsOrderField>
 			    by="category"
-			    label="カテゴリ"
+			    label={label ('common:categoryLabel')}
 			    currentOrder={order}
 			    defaultDirection={defaultDirection}/>
 		      </th>
-		      <th className="p-2 text-left whitespace-nowrap">状態</th>
-		      <th className="p-2 text-left whitespace-nowrap">別名</th>
-		      <th className="p-2 text-left whitespace-nowrap">上位タグ</th>
+		      <th className="p-2 text-left whitespace-nowrap">
+			{label ('common:stateLabel')}
+		      </th>
+		      <th className="p-2 text-left whitespace-nowrap">
+			{label ('aliases')}
+		      </th>
+		      <th className="p-2 text-left whitespace-nowrap">
+			{label ('parents')}
+		      </th>
 		      <th className="p-2 text-left whitespace-nowrap">
 			<SortHeader<FetchTagsOrderField>
 			    by="created_at"
-			    label="最初の記載日時"
+			    label={label ('firstRecordedColumn')}
 			    currentOrder={order}
 			    defaultDirection={defaultDirection}/>
 		      </th>
 		      <th className="p-2 text-left whitespace-nowrap">
 			<SortHeader<FetchTagsOrderField>
 			    by="updated_at"
-			    label="更新日時"
+			    label={label ('updatedAt')}
 			    currentOrder={order}
 			    defaultDirection={defaultDirection}/>
 		      </th>
@@ -420,8 +436,12 @@ const TagListPage: FC = () => {
 				withCount={false}/>
 			  </td>
 			  <td className="p-2 text-right">{row.postCount}</td>
-			  <td className="p-2">{CATEGORY_NAMES[row.category]}</td>
-			  <td className="p-2">{tagStateLabel (row.deprecatedAt)}</td>
+			  <td className="p-2">
+			    {label (`common:categories.${ row.category }`)}
+			  </td>
+			  <td className="p-2">
+			    {row.deprecatedAt ? label ('common:states.deprecated') : ''}
+			  </td>
 			  <td className="p-2">{row.aliases.join (' ')}</td>
 			  <td className="p-2">
 			    {row.parents.map (t => (
@@ -432,14 +452,26 @@ const TagListPage: FC = () => {
 				      withCount={false}/>
 				</span>))}
 			  </td>
-			  <td className="p-2">{dateString (row.createdAt)}</td>
-			  <td className="p-2">{dateString (row.updatedAt)}</td>
+			  <td className="p-2">
+			    <time dateTime={row.createdAt} lang={locale}>
+			      <LocalisedText language={locale}>
+				{localisedDateString (row.createdAt, locale)}
+			      </LocalisedText>
+			    </time>
+			  </td>
+			  <td className="p-2">
+			    <time dateTime={row.updatedAt} lang={locale}>
+			      <LocalisedText language={locale}>
+				{localisedDateString (row.updatedAt, locale)}
+			      </LocalisedText>
+			    </time>
+			  </td>
 			  <td className="p-2">
 			    <PrefetchLink
 				to={row.category === 'nico'
 				    ? `/posts/changes?external_tag=${ row.id }`
 				    : `/posts/changes?tag=${ row.id }`}>
-			      耕作履歴
+			      {label ('history')}
 			    </PrefetchLink>
 			  </td>
 			</tr>))}
@@ -448,7 +480,7 @@ const TagListPage: FC = () => {
 	      </div>
 
 	      <Pagination page={page} totalPages={totalPages}/>
-	    </div>) : '結果ないよ（笑）')}
+	    </div>) : (isError ? null : label ('empty')))}
       </MainArea>)
 }