// UI strings for both languages. Keys are grouped by the view they belong to;
// {placeholders} are filled by t().
const STRINGS = {
  de: {
    "common.cancel": "Abbrechen",
    "common.save": "Speichern",
    "common.create": "Anlegen",
    "common.request": "Anfragen",
    "common.search": "Suchen",
    "common.all": "Alle",
    "common.none": "Keine",
    "common.close": "Schließen",
    "common.edit": "Bearbeiten",
    "common.delete": "Löschen",
    "common.link": "Verbinden",
    "common.createAndLink": "Anlegen & verbinden",
    "common.selectAll": "Alle auswählen",
    "common.removeSelected": "Ausgewählte entfernen",
    "common.removeSelectedN": "Ausgewählte entfernen ({n})",
    "common.library": "Library",
    "common.type": "Typ",
    "common.title": "Titel",
    "common.authors": "Autor(en)",
    "common.author": "Autor",
    "common.narrator": "Sprecher",
    "common.series": "Serie",
    "common.volume": "Band",
    "common.year": "Jahr",
    "common.name": "Name",
    "common.path": "Pfad",
    "common.language": "Sprache",
    "common.score": "Score",
    "common.status": "Status",
    "common.noLibrary": "— keine Library —",
    "common.nothingHere": "Nichts hier.",
    "common.optionalForAll": "optional, für alle",
    "common.optional": "optional",
    "common.needLibraryFirst": "Erst eine Library für diesen Typ anlegen (Tab Libraries)",
    "common.creating": "Lege an…",
    "lang.german": "Deutsch",
    "lang.english": "Englisch",

    "nav.search": "Suche",
    "nav.missing": "Missing",
    "nav.imported": "Importiert",
    "nav.import": "Import",
    "nav.settings": "Libraries",
    "nav.langToggle": "Switch to English",

    "search.languageTitle": "Sprache der Ausgabe — filtert Ebook- und Audiobook-Suche",
    "search.allLanguages": "Alle Sprachen",
    "search.placeholder": "Titel, Autor oder ISBN…",
    "search.manual": "Manuell anlegen",
    "search.running": "Suche…",
    "search.wholeSeries": "Ganze Serie…",
    "search.requested": "✓ Angefragt",
    "search.emptyEbook": "Keine Treffer. Tipp: ISBN ohne Bindestriche oder Titel + Autor versuchen — und ggf. „Alle Sprachen“ wählen.",
    "search.emptyAudiobook": "Keine Treffer. Tipp: EAN/ISBN funktioniert bei Audible nicht — nach Titel/Autor suchen.",
    "search.emptyComic": "Keine Treffer bei AniList (Manga). Westliche Comics per „Manuell anlegen“ erfassen.",

    "manual.heading": "Manuell anfragen",
    "manual.volumeTo": "bis Band (Bulk, optional)",
    "manual.bulkHint": "Legt pro Band/Folge eine Anfrage an, z.B. 1 bis 300",
    "manual.externalId": "ISBN/ID",
    "manual.noLibraryChosen": "Keine Library gewählt",
    "manual.needStartVolume": "Für Bulk bitte Start-Band angeben",
    "manual.created": "Anfrage angelegt",
    "manual.createdN": "{n} Anfragen angelegt",

    "series.fallbackTitle": "Serie",
    "series.from": "von Nr.",
    "series.to": "bis Nr.",
    "series.loading": "{unit} werden gesucht…",
    "series.unitVolumes": "Bände",
    "series.unitEpisodes": "Folgen",
    "series.found": "{n} {unit} gefunden",
    "series.range": " (Nr. {from}–{to})",
    "series.noteEbook": ". Bände ohne Ausgabe in der gewählten Sprache stehen mit ihrem Originaltitel da.",
    "series.noteAudiobook": ". Audible hat keine Serien-Abfrage — einzelne Folgen können fehlen.",
    "series.gapVolumes": "… {n} Bände nicht bei Hardcover gefunden ({from}–{to})",
    "series.gapVolume": "… {n} Band nicht bei Hardcover gefunden ({from}–{to})",
    "series.gapEpisodes": "… {n} Folgen nicht bei Audible gefunden ({from}–{to})",
    "series.gapEpisode": "… {n} Folge nicht bei Audible gefunden ({from}–{to})",
    "series.requestN": "{n} anfragen",
    "series.needLibrary": "Erst eine {type}-Library anlegen (Tab Libraries)",
    "series.createdN": "{n} Anfragen angelegt",
    "series.skippedN": ", {n} bereits vorhanden",

    "list.allTypes": "Alle Typen",
    "list.allLibraries": "Alle Libraries",
    "list.filterPlaceholder": "Filtern (Titel/Autor/Serie)…",
    "list.view": "Ansicht",
    "list.viewList": "Liste",
    "list.viewSmall": "Kleine Symbole",
    "list.viewLarge": "Große Symbole",
    "list.confirmDeleteRequests": "{n} Anfrage(n) entfernen?",
    "list.confirmDeleteImported": "{n} Eintrag/Einträge entfernen? Die importierten Dateien in der Library bleiben erhalten.",
    "list.deletedN": "{n} entfernt",

    "detail.statusMissing": "fehlt noch",
    "detail.statusImported": "importiert",
    "detail.externalId": "ISBN/ASIN",
    "detail.retag": "Speichern & neu taggen",
    "detail.relocate": "Speichern & neu ablegen",
    "detail.relocateTitle": "Ordner und Dateinamen nach dem Schema der Library neu anlegen",
    "detail.relocating": "Lege ab…",
    "detail.relocated": "Neu abgelegt: {dest}",
    "detail.alreadyPlaced": "Liegt bereits richtig",
    "detail.retagging": "Tagge…",
    "detail.retagged": "{n} Datei(en) neu getaggt",
    "detail.saved": "Anfrage gespeichert",
    "detail.duplicateConfirm": "Trotzdem anlegen?",

    "import.scan": "Download-Ordner scannen",
    "import.splitDirs": "Ordner als Einzeldateien behandeln (z.B. Folgen-Sammlungen)",
    "import.scanning": "Scanne…",
    "import.candidates": "{n} Kandidat(en) in {dir}",
    "import.remaining": "{n} Kandidat(en) übrig — für den aktuellen Stand erneut scannen",
    "import.filterPlaceholder": "Filtern (Name/Pfad)…",
    "import.modeSuggested": "Nur mit Vorschlag",
    "import.modeUnassigned": "Nur ohne Zuordnung",
    "import.modeConflict": "Nur Konflikte",
    "import.formatTitle": "Nur Einträge mit diesem Dateiformat zeigen",
    "import.allFormats": "Alle Formate",
    "import.sortScan": "Reihenfolge: Scan",
    "import.sortScore": "Score absteigend",
    "import.sortName": "Name A–Z",
    "import.selectSuggested": "Alle mit Vorschlag auswählen",
    "import.selectAllTitle": "Alle Einträge der aktuellen Ansicht auswählen, auch ohne Zuordnung",
    "import.selectPage": "Diese Seite auswählen",
    "import.selectPageTitle": "Nur die Einträge dieser Seite auswählen, alle anderen abwählen",
    "import.deselectAll": "Alle abwählen",
    "import.merge": "Ausgewählte zusammenfassen",
    "import.mergeTitle": "Mehrteiler: ausgewählte Einträge als ein Hörbuch importieren",
    "import.fromNames": "Anfragen aus Ordnernamen",
    "import.fromNamesTitle": "Für ausgewählte Einträge ohne Zuordnung Anfragen aus den Ordnernamen anlegen",
    "import.colFile": "Datei/Ordner",
    "import.colAssignment": "Zuordnung",
    "import.prev": "← Zurück",
    "import.next": "Weiter →",
    "import.run": "Ausgewählte importieren",
    "import.skip": "— überspringen —",
    "import.appendGroup": "Bereits importiert — Teile anhängen",
    "import.quickTitle": "Metadaten suchen und Anfrage direkt verbinden",
    "import.unmerge": "Zusammenfassung wieder auflösen",
    "import.splitDir": "Ordner in einzelne Titel aufteilen",
    "import.parts": "{parts} Teile · {files} Dateien",
    "import.maybeSeparate": "{n} Titel?",
    "import.maybeSeparateTitle": "Die {n} Dateien tragen verschiedene Titel und sind je groß genug für ein ganzes Buch — mit ✂️ aufteilen",
    "import.libraryCellTitle": "Ziel-Library dieser Anfrage ändern",
    "import.conflict": "⚠ Konflikt",
    "import.conflictTitle": "Mehrere Einträge zeigen auf dieselbe Anfrage",
    "import.running": "läuft…",
    "import.done": "✓ importiert",
    "import.failed": "✗ Fehler",
    "import.pageInfo": "Seite {page}/{pages} · {total} Einträge{filtered} · {selected} ausgewählt",
    "import.filtered": " (gefiltert: {n})",
    "import.movedToLibrary": "„{title}\" → {library}",
    "import.selectedN": "{n} Einträge {what} ausgewählt",
    "import.selectedWithout": ", davon {n} ohne Zuordnung",
    "import.thisPage": "dieser Seite",
    "import.inTotal": "insgesamt",
    "import.nothingSelected": "Nichts ausgewählt",
    "import.needTwo": "Mindestens zwei Einträge auswählen",
    "import.sameTypeOnly": "Nur Einträge desselben Typs lassen sich zusammenfassen",
    "import.differentFolders": "Die Einträge liegen in verschiedenen Ordnern",
    "import.mergedN": "{n} Einträge als „{name}\" zusammengefasst ({files} Dateien)",
    "import.splitN": "„{name}\" in {n} Einzeltitel aufgeteilt",
    "import.nothingImported": "Nichts importiert: alle ausgewählten Einträge waren mehreren Anfragen zugeordnet — Filter „Nur Konflikte\" zeigt sie.",
    "import.summary": "{n} importiert",
    "import.summaryFailed": ", {n} Fehler",
    "import.summarySkipped": "{n} Anfrage(n) waren mehreren Einträgen zugeordnet und wurden übersprungen — Filter „Nur Konflikte\" zeigt sie.",
    "import.finished": "Import fertig",
    "import.finishedFailed": "Import fertig, {n} Fehler",
    "import.progressDone": "{total}/{total} · fertig",

    "names.heading": "Anfragen aus Ordnernamen",
    "names.intro": "{n} Einträge ohne Zuordnung ({type}). Titel und Folgennummer kommen aus dem Ordnernamen; Serie und Autor gelten für alle.",
    "names.more": "… und {n} weitere",
    "names.noneWithout": "Keine ausgewählten Einträge ohne Zuordnung",
    "names.result": "{created} Anfragen angelegt{skipped}, {linked} Einträge verbunden",
    "names.existed": ", {n} gab es schon",

    "conflict.heading": "Mehrfach zugeordnete Anfragen",
    "conflict.intro": "{n} Anfrage(n) sind mehreren Einträgen zugeordnet. Gehören die Einträge zusammen (Mehrteiler), lassen sie sich als ein Hörbuch importieren — sonst überspringst du sie, korrigierst die Zuordnung und importierst sie später.",
    "conflict.merge": "Als je ein Hörbuch zusammenfassen",
    "conflict.skip": "Konflikte überspringen, Rest importieren",

    "quick.heading": "Suchen & Anfragen",
    "quick.placeholder": "Titel/Serie suchen…",
    "quick.targetLibrary": "Ziel-Library",
    "quick.openRequests": "Offene Anfragen",
    "quick.reqFilter": "nach Titel, Autor, Serie filtern…",
    "quick.manualSummary": "Nicht bei Audible? Manuell anlegen",
    "quick.editSummary": "Felder anpassen",
    "quick.episodeVolume": "Folge/Band",
    "quick.searching": "Suche läuft…",
    "quick.episodeNote": "Folge {n} — nicht mitgesucht",
    "quick.matchingOpen": "Passende offene Requests:",
    "quick.hits": "{shown} von {total} Treffern ({open} offen)",
    "quick.noHits": "Kein Treffer unter {open} offenen Anfragen",
    "quick.linked": "Mit bestehendem Request verbunden",
    "quick.editTitle": "Felder vor dem Anlegen anpassen (z.B. Serie)",
    "quick.pickTitle": "Anfrage anlegen und mit diesem Eintrag verbinden",
    "quick.basedOn": "Übernommen von Audible: „{title}\" — Sprecher, Cover, Jahr und ASIN bleiben erhalten.",
    "quick.requestedAndLinked": "„{title}\" angefragt und verbunden",
    "quick.needTitle": "Titel angeben",

    "lib.heading": "Libraries",
    "lib.folderTemplate": "Ordner-Schema",
    "lib.fileTemplate": "Datei-Schema",
    "lib.new": "Neue Library",
    "lib.edit": "Library „{name}“ bearbeiten",
    "lib.namePlaceholder": "Name (z.B. Kids)",
    "lib.folderPlaceholder": "Ordner-Schema (optional)",
    "lib.filePlaceholder": "Datei-Schema (optional)",
    "lib.languageTitle": "Sprache der Ausgaben in dieser Library — filtert die Metadaten-Suche",
    "lib.anyLanguage": "Sprache: egal",
    "lib.placeholders": "Platzhalter: {Author} {Authors} {Narrator} {Narrators} {Title} {Year} {Series} {Volume} — {Author}/{Narrator} nennen den ersten Namen, {Authors}/{Narrators} alle. Leere Werte fallen samt Trenner weg.",
    "lib.confirmDelete": "Library löschen?",
    "lib.saved": "Library gespeichert — gilt für künftige Importe",
    "lib.created": "Library angelegt",
  },

  en: {
    "common.cancel": "Cancel",
    "common.save": "Save",
    "common.create": "Create",
    "common.request": "Request",
    "common.search": "Search",
    "common.all": "All",
    "common.none": "None",
    "common.close": "Close",
    "common.edit": "Edit",
    "common.delete": "Delete",
    "common.link": "Link",
    "common.createAndLink": "Create & link",
    "common.selectAll": "Select all",
    "common.removeSelected": "Remove selected",
    "common.removeSelectedN": "Remove selected ({n})",
    "common.library": "Library",
    "common.type": "Type",
    "common.title": "Title",
    "common.authors": "Author(s)",
    "common.author": "Author",
    "common.narrator": "Narrator",
    "common.series": "Series",
    "common.volume": "Volume",
    "common.year": "Year",
    "common.name": "Name",
    "common.path": "Path",
    "common.language": "Language",
    "common.score": "Score",
    "common.status": "Status",
    "common.noLibrary": "— no library —",
    "common.nothingHere": "Nothing here.",
    "common.optionalForAll": "optional, for all",
    "common.optional": "optional",
    "common.needLibraryFirst": "Create a library for this type first (Libraries tab)",
    "common.creating": "Creating…",
    "lang.german": "German",
    "lang.english": "English",

    "nav.search": "Search",
    "nav.missing": "Missing",
    "nav.imported": "Imported",
    "nav.import": "Import",
    "nav.settings": "Libraries",
    "nav.langToggle": "Auf Deutsch umschalten",

    "search.languageTitle": "Edition language — filters the ebook and audiobook search",
    "search.allLanguages": "All languages",
    "search.placeholder": "Title, author or ISBN…",
    "search.manual": "Add manually",
    "search.running": "Searching…",
    "search.wholeSeries": "Whole series…",
    "search.requested": "✓ Requested",
    "search.emptyEbook": "No hits. Try the ISBN without dashes, or title + author — and maybe pick “All languages”.",
    "search.emptyAudiobook": "No hits. EAN/ISBN does not work on Audible — search by title/author.",
    "search.emptyComic": "No hits on AniList (manga). Add western comics via “Add manually”.",

    "manual.heading": "Request manually",
    "manual.volumeTo": "to volume (bulk, optional)",
    "manual.bulkHint": "Creates one request per volume/episode, e.g. 1 to 300",
    "manual.externalId": "ISBN/ID",
    "manual.noLibraryChosen": "No library chosen",
    "manual.needStartVolume": "Bulk needs a starting volume",
    "manual.created": "Request created",
    "manual.createdN": "{n} requests created",

    "series.fallbackTitle": "Series",
    "series.from": "from no.",
    "series.to": "to no.",
    "series.loading": "Looking for {unit}…",
    "series.unitVolumes": "volumes",
    "series.unitEpisodes": "episodes",
    "series.found": "{n} {unit} found",
    "series.range": " (no. {from}–{to})",
    "series.noteEbook": ". Volumes without an edition in the chosen language keep their original title.",
    "series.noteAudiobook": ". Audible has no series query — single episodes can be missing.",
    "series.gapVolumes": "… {n} volumes not found on Hardcover ({from}–{to})",
    "series.gapVolume": "… {n} volume not found on Hardcover ({from}–{to})",
    "series.gapEpisodes": "… {n} episodes not found on Audible ({from}–{to})",
    "series.gapEpisode": "… {n} episode not found on Audible ({from}–{to})",
    "series.requestN": "Request {n}",
    "series.needLibrary": "Create an {type} library first (Libraries tab)",
    "series.createdN": "{n} requests created",
    "series.skippedN": ", {n} already there",

    "list.allTypes": "All types",
    "list.allLibraries": "All libraries",
    "list.filterPlaceholder": "Filter (title/author/series)…",
    "list.view": "View",
    "list.viewList": "List",
    "list.viewSmall": "Small icons",
    "list.viewLarge": "Large icons",
    "list.confirmDeleteRequests": "Remove {n} request(s)?",
    "list.confirmDeleteImported": "Remove {n} entr(y/ies)? The imported files stay in the library.",
    "list.deletedN": "{n} removed",

    "detail.statusMissing": "still missing",
    "detail.statusImported": "imported",
    "detail.externalId": "ISBN/ASIN",
    "detail.retag": "Save & re-tag",
    "detail.relocate": "Save & re-file",
    "detail.relocateTitle": "Rebuild folder and file names from the library's scheme",
    "detail.relocating": "Filing…",
    "detail.relocated": "Re-filed: {dest}",
    "detail.alreadyPlaced": "Already in the right place",
    "detail.retagging": "Tagging…",
    "detail.retagged": "{n} file(s) re-tagged",
    "detail.saved": "Request saved",
    "detail.duplicateConfirm": "Create anyway?",

    "import.scan": "Scan download folder",
    "import.splitDirs": "Treat folders as single files (e.g. episode collections)",
    "import.scanning": "Scanning…",
    "import.candidates": "{n} candidate(s) in {dir}",
    "import.remaining": "{n} candidate(s) left — scan again for the current state",
    "import.filterPlaceholder": "Filter (name/path)…",
    "import.modeSuggested": "With suggestion only",
    "import.modeUnassigned": "Unassigned only",
    "import.modeConflict": "Conflicts only",
    "import.formatTitle": "Show only entries with this file format",
    "import.allFormats": "All formats",
    "import.sortScan": "Order: scan",
    "import.sortScore": "Score descending",
    "import.sortName": "Name A–Z",
    "import.selectSuggested": "Select all with a suggestion",
    "import.selectAllTitle": "Select every entry of the current view, unassigned ones too",
    "import.selectPage": "Select this page",
    "import.selectPageTitle": "Select only this page's entries, deselect all others",
    "import.deselectAll": "Deselect all",
    "import.merge": "Merge selected",
    "import.mergeTitle": "Multi-part title: import the selected entries as one audiobook",
    "import.fromNames": "Requests from folder names",
    "import.fromNamesTitle": "Create requests from the folder names of the selected unassigned entries",
    "import.colFile": "File/folder",
    "import.colAssignment": "Assignment",
    "import.prev": "← Back",
    "import.next": "Next →",
    "import.run": "Import selected",
    "import.skip": "— skip —",
    "import.appendGroup": "Already imported — append parts",
    "import.quickTitle": "Search metadata and link the request right away",
    "import.unmerge": "Undo the merge",
    "import.splitDir": "Split the folder into single titles",
    "import.parts": "{parts} parts · {files} files",
    "import.maybeSeparate": "{n} titles?",
    "import.maybeSeparateTitle": "The {n} files carry different titles and are each big enough for a whole book — split with ✂️",
    "import.libraryCellTitle": "Change this request's target library",
    "import.conflict": "⚠ Conflict",
    "import.conflictTitle": "Several entries point at the same request",
    "import.running": "running…",
    "import.done": "✓ imported",
    "import.failed": "✗ Error",
    "import.pageInfo": "Page {page}/{pages} · {total} entries{filtered} · {selected} selected",
    "import.filtered": " (filtered: {n})",
    "import.movedToLibrary": "“{title}” → {library}",
    "import.selectedN": "{n} entries {what} selected",
    "import.selectedWithout": ", {n} of them unassigned",
    "import.thisPage": "on this page",
    "import.inTotal": "in total",
    "import.nothingSelected": "Nothing selected",
    "import.needTwo": "Select at least two entries",
    "import.sameTypeOnly": "Only entries of the same type can be merged",
    "import.differentFolders": "The entries live in different folders",
    "import.mergedN": "{n} entries merged as “{name}” ({files} files)",
    "import.splitN": "“{name}” split into {n} single titles",
    "import.nothingImported": "Nothing imported: every selected entry was assigned to several requests — the “Conflicts only” filter shows them.",
    "import.summary": "{n} imported",
    "import.summaryFailed": ", {n} failed",
    "import.summarySkipped": "{n} request(s) were assigned to several entries and were skipped — the “Conflicts only” filter shows them.",
    "import.finished": "Import finished",
    "import.finishedFailed": "Import finished, {n} failed",
    "import.progressDone": "{total}/{total} · done",

    "names.heading": "Requests from folder names",
    "names.intro": "{n} unassigned entries ({type}). Title and episode number come from the folder name; series and author apply to all of them.",
    "names.more": "… and {n} more",
    "names.noneWithout": "No selected entries without an assignment",
    "names.result": "{created} requests created{skipped}, {linked} entries linked",
    "names.existed": ", {n} already existed",

    "conflict.heading": "Requests assigned more than once",
    "conflict.intro": "{n} request(s) are assigned to several entries. If those entries belong together (a multi-part title), they can be imported as one audiobook — otherwise skip them, fix the assignment and import them later.",
    "conflict.merge": "Merge each into one audiobook",
    "conflict.skip": "Skip conflicts, import the rest",

    "quick.heading": "Search & request",
    "quick.placeholder": "Search title/series…",
    "quick.targetLibrary": "Target library",
    "quick.openRequests": "Open requests",
    "quick.reqFilter": "filter by title, author, series…",
    "quick.manualSummary": "Not on Audible? Add manually",
    "quick.editSummary": "Adjust the fields",
    "quick.episodeVolume": "Episode/volume",
    "quick.searching": "Searching…",
    "quick.episodeNote": "Episode {n} — not part of the search",
    "quick.matchingOpen": "Matching open requests:",
    "quick.hits": "{shown} of {total} hits ({open} open)",
    "quick.noHits": "No hit among {open} open requests",
    "quick.linked": "Linked to the existing request",
    "quick.editTitle": "Adjust the fields before creating (e.g. the series)",
    "quick.pickTitle": "Create the request and link it to this entry",
    "quick.basedOn": "Taken from Audible: “{title}” — narrator, cover, year and ASIN are kept.",
    "quick.requestedAndLinked": "“{title}” requested and linked",
    "quick.needTitle": "Enter a title",

    "lib.heading": "Libraries",
    "lib.folderTemplate": "Folder scheme",
    "lib.fileTemplate": "File scheme",
    "lib.new": "New library",
    "lib.edit": "Edit library “{name}”",
    "lib.namePlaceholder": "Name (e.g. Kids)",
    "lib.folderPlaceholder": "Folder scheme (optional)",
    "lib.filePlaceholder": "File scheme (optional)",
    "lib.languageTitle": "Language of this library's editions — filters the metadata search",
    "lib.anyLanguage": "Language: any",
    "lib.placeholders": "Placeholders: {Author} {Authors} {Narrator} {Narrators} {Title} {Year} {Series} {Volume} — {Author}/{Narrator} name the first one, {Authors}/{Narrators} all of them. Empty values drop out with their separator.",
    "lib.confirmDelete": "Delete library?",
    "lib.saved": "Library saved — applies to future imports",
    "lib.created": "Library created",
  },
};

const LANG_KEY = "wordarr.lang";

function initialLang() {
  try {
    const saved = localStorage.getItem(LANG_KEY);
    if (saved && STRINGS[saved]) return saved;
  } catch {}
  return (navigator.language || "en").startsWith("de") ? "de" : "en";
}

let lang = initialLang();

// {Placeholders} of the naming scheme must survive, so only known vars are replaced
function t(key, vars) {
  let s = STRINGS[lang][key] ?? STRINGS.en[key] ?? key;
  if (vars) {
    for (const [name, value] of Object.entries(vars)) {
      s = s.split("{" + name + "}").join(String(value));
    }
  }
  return s;
}

const I18N_ATTRS = { "i18nPlaceholder": "placeholder", "i18nTitle": "title", "i18nAria": "aria-label" };

function applyI18n(root = document) {
  root.querySelectorAll("[data-i18n]").forEach((el) => (el.textContent = t(el.dataset.i18n)));
  for (const [data, attr] of Object.entries(I18N_ATTRS)) {
    root.querySelectorAll(`[data-${data.replace(/[A-Z]/g, (c) => "-" + c.toLowerCase())}]`)
      .forEach((el) => el.setAttribute(attr, t(el.dataset[data])));
  }
  document.documentElement.lang = lang;
}

function setLang(next) {
  lang = next;
  try { localStorage.setItem(LANG_KEY, next); } catch {}
  applyI18n();
  if (typeof onLangChange === "function") onLangChange();
}