Add DE/EN/PL i18n with browser-language detection and per-user override

- STRINGS object in app.js with all UI strings in de/en/pl
- tr() function, ldoc() locale-aware date formatting
- tpl() auto-translates data-t/data-ph/data-val attributes on clone
- app.html.twig: data-t attributes on all template static text, language picker in data menu
- locale CHAR(2) column on users table; GET /api/me returns locale; PATCH /api/me accepts locale
- setLocale() persists to API + localStorage; applyLocale() reads user.locale → localStorage → navigator.language

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

migrations/Version20260430100000.php

@@ -0,0 +1,21 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DoctrineMigrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\AbstractMigration;
+
+final class Version20260430100000 extends AbstractMigration
+{
+    public function up(Schema $schema): void
+    {
+        $this->addSql('ALTER TABLE users ADD COLUMN locale CHAR(2) DEFAULT NULL');
+    }
+
+    public function down(Schema $schema): void
+    {
+        $this->addSql('ALTER TABLE users DROP COLUMN locale');
+    }
+}

public/app.js

@@ -2,6 +2,188 @@ var TODAY = new Date(); TODAY.setHours(0,0,0,0);
 var goals = [], prefs, selDay = {}, addAmt = {}, renamingId = null, renameVal = '', collapsed = {};
 var userName = '';
 
+var STRINGS = {
+  de: {
+    hint:'Menü → "Zum Startbildschirm" für App-Icon',
+    emptyLine1:'Noch keine Ziele.',emptyLine2:'Tippe auf + um zu starten.',
+    noEntry:'Noch kein Eintrag',log:'Eintragen',
+    noch:'Noch',dAbbr:'T',endet:'endet',todayShort:'heute',total:'total',
+    todayHeading:'Heute',done2:'Gemacht',dailyGoal:'Tagesziel',remaining:'Noch',
+    history:'Verlauf — heute & gestern bearbeitbar',
+    legBuf:'Puffer',legDone:'Erreicht',legPartial:'Teilweise',legMissed:'Verpasst',
+    delGoal:'Ziel löschen',
+    qbLabel:'Quick-Buchen',openLabel:'Offen',doneToday:'Heute erledigt',
+    hello:'Hallo {n}!',
+    confirmDelete:'Ziel wirklich löschen?',errDelete:'Fehler beim Löschen',errSave:'Speicherfehler',
+    loginTitle:'Anmelden',emailLabel:'E-Mail',passwordLabel:'Passwort',loginBtn:'Anmelden',
+    forgotPw:'Passwort vergessen?',
+    loginErrEmpty:'Bitte E-Mail und Passwort eingeben',
+    loginErrWrong:'Falsche E-Mail oder Passwort',loginErrRate:'Zu viele Versuche',loginErrConn:'Verbindungsfehler',
+    forgotTitle:'Passwort vergessen',forgotSub:'Wir schicken dir einen Reset-Link',
+    sendLink:'Link senden',back:'Zurück',
+    emailSentTitle:'E-Mail gesendet',
+    emailSentSub:'Falls die Adresse bekannt ist, erhältst du in Kürze einen Reset-Link.',
+    ok:'OK',
+    resetTitle:'Neues Passwort',newPwLabel:'Neues Passwort',setPw:'Passwort setzen',min8:'mind. 8 Zeichen',
+    pwChangedTitle:'Passwort geändert',pwChangedSub:'Du kannst dich jetzt anmelden.',
+    changeNameTitle:'Name ändern',yourName:'Dein Name',save:'Speichern',cancel:'Abbrechen',
+    errNameEmpty:'Name darf nicht leer sein',errNameSave:'Fehler beim Speichern',nameSaved:'Name gespeichert',
+    changePwTitle:'Passwort ändern',currentPwLabel:'Aktuelles Passwort',
+    newPwConfLabel:'Neues Passwort bestätigen',changePwBtn:'Ändern',
+    errPwMismatch:'Die neuen Passwörter stimmen nicht überein',pwChanged:'Passwort geändert',
+    registerTitle:'Konto erstellen',registerSub:'Du wurdest eingeladen',
+    namePlaceholder:'Wie sollen wir dich nennen?',pwConfLabel:'Passwort bestätigen',
+    pwPlaceholder:'Passwort wiederholen',registerBtn:'Registrieren',
+    errPwMismatch2:'Passwörter stimmen nicht überein',errFillAll:'Bitte alle Felder ausfüllen',
+    newGoalTitle:'Neues Ziel',exerciseLabel:'Übung / Gewohnheit',exercisePlaceholder:'Liegestütz, Plank …',
+    unitLabel:'Einheit',unitDefault:'Stück',daysLabel:'Dauer in Tagen',
+    dailyLabel:'Tagesziel',weeklyLabel:'Wochenziel',startGoal:'Ziel starten',errCreate:'Fehler beim Erstellen',
+    dataMenuTitle:'Daten verwalten',dataMenuSub:'Export, Import und Backup',
+    exportLabel:'Exportieren',exportSub:'Alle Ziele als JSON-Datei speichern',
+    importLabel:'Importieren',importSub:'Backup laden oder zusammenführen',
+    inviteLabel:'Freund einladen',inviteSub:'Einladungslink generieren',
+    inviteListLabel:'Meine Einladungen',inviteListSub:'Status aller gesendeten Einladungen',
+    changeName:'Name ändern',changePw:'Passwort ändern',logout:'Abmelden',close:'Schließen',
+    clearAll:'Alle Daten löschen',clearAllSub:'Kann nicht rückgängig gemacht werden',
+    confirmClear:'Alle Daten löschen?',
+    inviteFormTitle:'Freund einladen',inviteFormSub:'Link gilt 7 Tage und kann nur einmal verwendet werden',
+    inviteNameLabel:'Name (für deine Übersicht)',inviteNamePlaceholder:'z.B. Max',
+    generateLink:'Link generieren',inviteLinkTitle:'Einladungslink',
+    copyLink:'Link kopieren',linkCopied:'Link kopiert!',errGenerate:'Fehler beim Generieren',
+    noInvites:'Noch keine Einladungen verschickt',
+    statusPending:'Ausstehend',statusUsed:'Angenommen',statusExpired:'Abgelaufen',
+    errLoad:'Fehler beim Laden',
+    confirmImport:'{n} Ziel(e) importieren?',importDone:'{n} Ziel(e) importiert.',invalidFormat:'Ungültiges Format',
+    linkLabel:'Link',doneLabel:'gemacht',ofLabel:'von',
+    gestern:'Gestern',heute:'Heute',
+    expiresAt:'läuft ab:',acceptedBy:'→',
+  },
+  en: {
+    hint:'Menu → "Add to Home Screen" for app icon',
+    emptyLine1:'No goals yet.',emptyLine2:'Tap + to get started.',
+    noEntry:'No entries yet',log:'Log',
+    noch:'Left',dAbbr:'d',endet:'ends',todayShort:'today',total:'total',
+    todayHeading:'Today',done2:'Done',dailyGoal:'Daily goal',remaining:'Left',
+    history:'History — today & yesterday editable',
+    legBuf:'Buffer',legDone:'Reached',legPartial:'Partial',legMissed:'Missed',
+    delGoal:'Delete goal',
+    qbLabel:'Quick-log',openLabel:'Open',doneToday:'Done today',
+    hello:'Hello {n}!',
+    confirmDelete:'Really delete this goal?',errDelete:'Delete failed',errSave:'Save failed',
+    loginTitle:'Sign in',emailLabel:'E-Mail',passwordLabel:'Password',loginBtn:'Sign in',
+    forgotPw:'Forgot password?',
+    loginErrEmpty:'Please enter email and password',
+    loginErrWrong:'Wrong email or password',loginErrRate:'Too many attempts',loginErrConn:'Connection error',
+    forgotTitle:'Forgot password',forgotSub:"We'll send you a reset link",
+    sendLink:'Send link',back:'Back',
+    emailSentTitle:'Email sent',
+    emailSentSub:"If the address is registered, you'll receive a reset link shortly.",
+    ok:'OK',
+    resetTitle:'New password',newPwLabel:'New password',setPw:'Set password',min8:'at least 8 characters',
+    pwChangedTitle:'Password changed',pwChangedSub:'You can now sign in.',
+    changeNameTitle:'Change name',yourName:'Your name',save:'Save',cancel:'Cancel',
+    errNameEmpty:'Name cannot be empty',errNameSave:'Save failed',nameSaved:'Name saved',
+    changePwTitle:'Change password',currentPwLabel:'Current password',
+    newPwConfLabel:'Confirm new password',changePwBtn:'Change',
+    errPwMismatch:"The new passwords don't match",pwChanged:'Password changed',
+    registerTitle:'Create account',registerSub:"You've been invited",
+    namePlaceholder:'What should we call you?',pwConfLabel:'Confirm password',
+    pwPlaceholder:'Repeat password',registerBtn:'Register',
+    errPwMismatch2:"Passwords don't match",errFillAll:'Please fill in all fields',
+    newGoalTitle:'New goal',exerciseLabel:'Exercise / Habit',exercisePlaceholder:'Push-ups, Plank …',
+    unitLabel:'Unit',unitDefault:'reps',daysLabel:'Duration (days)',
+    dailyLabel:'Daily goal',weeklyLabel:'Weekly goal',startGoal:'Start goal',errCreate:'Create failed',
+    dataMenuTitle:'Manage data',dataMenuSub:'Export, Import and Backup',
+    exportLabel:'Export',exportSub:'Save all goals as JSON file',
+    importLabel:'Import',importSub:'Load or merge backup',
+    inviteLabel:'Invite friend',inviteSub:'Generate invite link',
+    inviteListLabel:'My invitations',inviteListSub:'Status of all sent invitations',
+    changeName:'Change name',changePw:'Change password',logout:'Sign out',close:'Close',
+    clearAll:'Delete all data',clearAllSub:'Cannot be undone',
+    confirmClear:'Delete all data?',
+    inviteFormTitle:'Invite friend',inviteFormSub:'Link valid 7 days, single use',
+    inviteNameLabel:'Name (for your reference)',inviteNamePlaceholder:'e.g. Max',
+    generateLink:'Generate link',inviteLinkTitle:'Invite link',
+    copyLink:'Copy link',linkCopied:'Link copied!',errGenerate:'Generate failed',
+    noInvites:'No invitations sent yet',
+    statusPending:'Pending',statusUsed:'Accepted',statusExpired:'Expired',
+    errLoad:'Load failed',
+    confirmImport:'Import {n} goal(s)?',importDone:'{n} goal(s) imported.',invalidFormat:'Invalid format',
+    linkLabel:'Link',doneLabel:'done',ofLabel:'of',
+    gestern:'Yesterday',heute:'Today',
+    expiresAt:'expires:',acceptedBy:'→',
+  },
+  pl: {
+    hint:'Menu → "Dodaj do ekranu głównego" aby zainstalować',
+    emptyLine1:'Brak celów.',emptyLine2:'Dotknij +, aby zacząć.',
+    noEntry:'Brak wpisów',log:'Zapisz',
+    noch:'Jeszcze',dAbbr:'d',endet:'kończy',todayShort:'dziś',total:'łącznie',
+    todayHeading:'Dziś',done2:'Wykonano',dailyGoal:'Cel dzienny',remaining:'Pozostało',
+    history:'Historia — dziś i wczoraj edytowalne',
+    legBuf:'Zapas',legDone:'Osiągnięto',legPartial:'Częściowo',legMissed:'Pominięto',
+    delGoal:'Usuń cel',
+    qbLabel:'Szybki wpis',openLabel:'Otwarte',doneToday:'Dziś ukończone',
+    hello:'Cześć {n}!',
+    confirmDelete:'Na pewno usunąć cel?',errDelete:'Błąd podczas usuwania',errSave:'Błąd zapisu',
+    loginTitle:'Zaloguj się',emailLabel:'E-Mail',passwordLabel:'Hasło',loginBtn:'Zaloguj',
+    forgotPw:'Zapomniałeś hasła?',
+    loginErrEmpty:'Podaj e-mail i hasło',
+    loginErrWrong:'Błędny e-mail lub hasło',loginErrRate:'Zbyt wiele prób',loginErrConn:'Błąd połączenia',
+    forgotTitle:'Zapomniane hasło',forgotSub:'Wyślemy Ci link do resetu',
+    sendLink:'Wyślij link',back:'Wróć',
+    emailSentTitle:'E-mail wysłany',
+    emailSentSub:'Jeśli adres jest zarejestrowany, wkrótce otrzymasz link resetujący.',
+    ok:'OK',
+    resetTitle:'Nowe hasło',newPwLabel:'Nowe hasło',setPw:'Ustaw hasło',min8:'min. 8 znaków',
+    pwChangedTitle:'Hasło zmienione',pwChangedSub:'Możesz się teraz zalogować.',
+    changeNameTitle:'Zmień nazwę',yourName:'Twoje imię',save:'Zapisz',cancel:'Anuluj',
+    errNameEmpty:'Imię nie może być puste',errNameSave:'Błąd zapisu',nameSaved:'Imię zapisano',
+    changePwTitle:'Zmień hasło',currentPwLabel:'Aktualne hasło',
+    newPwConfLabel:'Potwierdź nowe hasło',changePwBtn:'Zmień',
+    errPwMismatch:'Nowe hasła się nie zgadzają',pwChanged:'Hasło zmienione',
+    registerTitle:'Utwórz konto',registerSub:'Zostałeś zaproszony',
+    namePlaceholder:'Jak mamy Cię nazywać?',pwConfLabel:'Potwierdź hasło',
+    pwPlaceholder:'Powtórz hasło',registerBtn:'Zarejestruj',
+    errPwMismatch2:'Hasła się nie zgadzają',errFillAll:'Wypełnij wszystkie pola',
+    newGoalTitle:'Nowy cel',exerciseLabel:'Ćwiczenie / Nawyk',exercisePlaceholder:'Pompki, Plank …',
+    unitLabel:'Jednostka',unitDefault:'szt.',daysLabel:'Czas trwania (dni)',
+    dailyLabel:'Cel dzienny',weeklyLabel:'Cel tygodniowy',startGoal:'Rozpocznij cel',errCreate:'Błąd tworzenia',
+    dataMenuTitle:'Zarządzaj danymi',dataMenuSub:'Eksport, import i kopia zapasowa',
+    exportLabel:'Eksportuj',exportSub:'Zapisz wszystkie cele jako plik JSON',
+    importLabel:'Importuj',importSub:'Załaduj lub połącz kopię zapasową',
+    inviteLabel:'Zaproś znajomego',inviteSub:'Wygeneruj link zaproszenia',
+    inviteListLabel:'Moje zaproszenia',inviteListSub:'Status wszystkich wysłanych zaproszeń',
+    changeName:'Zmień nazwę',changePw:'Zmień hasło',logout:'Wyloguj',close:'Zamknij',
+    clearAll:'Usuń wszystkie dane',clearAllSub:'Nie można cofnąć',
+    confirmClear:'Usunąć wszystkie dane?',
+    inviteFormTitle:'Zaproś znajomego',inviteFormSub:'Link ważny 7 dni, jednorazowy',
+    inviteNameLabel:'Nazwa (dla Twojej ewidencji)',inviteNamePlaceholder:'np. Max',
+    generateLink:'Wygeneruj link',inviteLinkTitle:'Link zaproszenia',
+    copyLink:'Kopiuj link',linkCopied:'Link skopiowany!',errGenerate:'Błąd generowania',
+    noInvites:'Brak wysłanych zaproszeń',
+    statusPending:'Oczekujący',statusUsed:'Zaakceptowany',statusExpired:'Wygasły',
+    errLoad:'Błąd ładowania',
+    confirmImport:'Importować {n} cel(e)?',importDone:'Zaimportowano {n} cel(e).',invalidFormat:'Nieprawidłowy format',
+    linkLabel:'Link',doneLabel:'wykonano',ofLabel:'z',
+    gestern:'Wczoraj',heute:'Dziś',
+    expiresAt:'wygasa:',acceptedBy:'→',
+  }
+};
+
+var LOCALE = 'de';
+
+function tr(key){ return (STRINGS[LOCALE]||STRINGS.de)[key]||STRINGS.de[key]||key; }
+function ldoc(){ return LOCALE==='de'?'de-DE':LOCALE==='pl'?'pl-PL':'en-GB'; }
+
+function setLocale(lang, save){
+  LOCALE = lang;
+  if(save){
+    api('PATCH','me',{locale:lang}).catch(function(){});
+    localStorage.setItem('zt_locale',lang);
+  }
+  render(); updateHeader();
+}
+
 function loadPref(k,def){ try{ return JSON.parse(localStorage.getItem(k)||def); }catch(e){ return JSON.parse(def); } }
 function saveP(){ localStorage.setItem('zt_p',JSON.stringify(prefs)); }
 prefs = loadPref('zt_p','{}');
@@ -9,8 +191,8 @@ prefs = loadPref('zt_p','{}');
 function tOff(g){ return Math.round((TODAY - new Date(g.start))/86400000); }
 function o2d(g,i){ var d=new Date(new Date(g.start).getTime()+i*86400000); d.setHours(0,0,0,0); return d; }
 function dTot(g,o){ return (g.sets[String(o)]||[]).reduce(function(a,b){return a+b.amount;},0); }
-function fd(d){ return d.toLocaleDateString('de-DE',{weekday:'short',day:'numeric',month:'short'}); }
+function fd(d){ return d.toLocaleDateString(ldoc(),{weekday:'short',day:'numeric',month:'short'}); }
-function fs(d){ return d.toLocaleDateString('de-DE',{day:'numeric',month:'short'}); }
+function fs(d){ return d.toLocaleDateString(ldoc(),{day:'numeric',month:'short'}); }
 function editable(g,o){ var t=tOff(g); return o===t||o===t-1; }
 function now(){ var n=new Date(); return String(n.getHours()).padStart(2,'0')+':'+String(n.getMinutes()).padStart(2,'0'); }
 
@@ -87,7 +269,7 @@ function saveGoal(g){
   api('PATCH','goals/'+g.id,{name:g.name,unit:g.unit,daily:g.daily,days:g.days,start:g.start,sets:g.sets})
     .catch(function(e){
       if(e.status===401){ showLogin(); }
-      else showToast('Speicherfehler');
+      else showToast(tr('errSave'));
     });
 }
 
@@ -115,10 +297,10 @@ function remSet(gid,off,idx){
   g.sets[String(off)].splice(idx,1); saveGoal(g); render();
 }
 function delGoal(id){
-  if(!confirm('Ziel wirklich löschen?')) return;
+  if(!confirm(tr('confirmDelete'))) return;
   goals=goals.filter(function(g){return g.id!==id;});
   render();
-  api('DELETE','goals/'+id).catch(function(){ showToast('Fehler beim Löschen'); });
+  api('DELETE','goals/'+id).catch(function(){ showToast(tr('errDelete')); });
 }
 function selD(gid,off){
   var g=goals.filter(function(x){return x.id===gid;})[0];
@@ -140,7 +322,11 @@ function cancelRen(){ renamingId=null; render(); }
 // ── Template-Helper ───────────────────────────────────────────────────────────
 
 function tpl(id){
-  return document.getElementById(id).content.cloneNode(true).firstElementChild;
+  var el=document.getElementById(id).content.cloneNode(true).firstElementChild;
+  el.querySelectorAll('[data-t]').forEach(function(n){ n.textContent=tr(n.dataset.t); });
+  el.querySelectorAll('[data-ph]').forEach(function(n){ n.placeholder=tr(n.dataset.ph); });
+  el.querySelectorAll('[data-val]').forEach(function(n){ n.value=tr(n.dataset.val); });
+  return el;
 }
 
 // ── Overlays ──────────────────────────────────────────────────────────────────
@@ -176,14 +362,14 @@ function showLogin(err){
   c.querySelector('.lf-fgt').onclick=function(){showForgotPassword();};
   sub.onclick=function(){
     var ev=email.value.trim(), pv=pass.value;
-    if(!ev||!pv){ var errEl=c.querySelector('.login-err'); errEl.textContent='Bitte E-Mail und Passwort eingeben'; errEl.style.display=''; return; }
+    if(!ev||!pv){ var errEl=c.querySelector('.login-err'); errEl.textContent=tr('loginErrEmpty'); errEl.style.display=''; return; }
     sub.disabled=true; sub.textContent='…';
     api('POST','login',{email:ev,password:pv})
       .then(function(){ return loadGoals(); })
       .then(function(g){ goals=g; closeOv(); render(); })
       .catch(function(err){
-        sub.disabled=false; sub.textContent='Anmelden';
+        sub.disabled=false; sub.textContent=tr('loginBtn');
-        showLogin(err.status===401?'Falsche E-Mail oder Passwort':err.status===429?'Zu viele Versuche':'Verbindungsfehler');
+        showLogin(err.status===401?tr('loginErrWrong'):err.status===429?tr('loginErrRate'):tr('loginErrConn'));
       });
   };
 }
@@ -206,7 +392,7 @@ function showForgotPassword(){
         showSheet(conf,false);
       })
       .catch(function(err){
-        sub.disabled=false; sub.textContent='Link senden';
+        sub.disabled=false; sub.textContent=tr('sendLink');
         errEl.textContent=err.message||'Fehler'; errEl.style.display='';
       });
   };
@@ -229,7 +415,7 @@ function showResetPassword(selector,token){
         showSheet(conf,false);
       })
       .catch(function(err){
-        sub.disabled=false; sub.textContent='Passwort setzen';
+        sub.disabled=false; sub.textContent=tr('setPw');
         errEl.textContent=err.message||'Fehler'; errEl.style.display='';
       });
   };
@@ -247,12 +433,12 @@ function showChangePassword(){
   sub.onclick=function(){
     var o=oldP.value, n=newP.value, n2=newP2.value;
     if(!o||!n||!n2) return;
-    if(n!==n2){ errEl.textContent='Die neuen Passwörter stimmen nicht überein'; errEl.style.display=''; return; }
+    if(n!==n2){ errEl.textContent=tr('errPwMismatch'); errEl.style.display=''; return; }
     sub.disabled=true; sub.textContent='…';
     api('POST','change-password',{old_password:o,new_password:n})
-      .then(function(){ showToast('Passwort geändert'); closeOv(); })
+      .then(function(){ showToast(tr('pwChanged')); closeOv(); })
       .catch(function(err){
-        sub.disabled=false; sub.textContent='Ändern';
+        sub.disabled=false; sub.textContent=tr('changePwBtn');
         errEl.textContent=err.message||'Fehler'; errEl.style.display='';
       });
   };
@@ -271,18 +457,18 @@ function showRegister(token){
   email.onkeydown=function(e){if(e.key==='Enter')pass.focus();};
   pass.onkeydown=function(e){if(e.key==='Enter')pass2.focus();};
   pass2.onkeydown=function(e){if(e.key==='Enter')sub.click();};
-  function checkMatch(){ if(pass2.value&&pass.value!==pass2.value){ errEl.textContent='Passwörter stimmen nicht überein'; errEl.style.display=''; } else { errEl.style.display='none'; } }
+  function checkMatch(){ if(pass2.value&&pass.value!==pass2.value){ errEl.textContent=tr('errPwMismatch2'); errEl.style.display=''; } else { errEl.style.display='none'; } }
   pass.oninput=checkMatch; pass2.oninput=checkMatch;
   sub.onclick=function(){
     var nv=nameInp.value.trim(), ev=email.value.trim(), pv=pass.value;
-    if(!nv||!ev||!pv){ errEl.textContent='Bitte alle Felder ausfüllen'; errEl.style.display=''; return; }
+    if(!nv||!ev||!pv){ errEl.textContent=tr('errFillAll'); errEl.style.display=''; return; }
-    if(pv!==pass2.value){ errEl.textContent='Passwörter stimmen nicht überein'; errEl.style.display=''; return; }
+    if(pv!==pass2.value){ errEl.textContent=tr('errPwMismatch2'); errEl.style.display=''; return; }
     sub.disabled=true; sub.textContent='…';
     api('POST','register',{name:nv,email:ev,password:pv,token:token})
       .then(function(r){ userName=r.name||''; return loadGoals(); })
       .then(function(g){ goals=g; closeOv(); updateHeader(); render(); })
       .catch(function(err){
-        sub.disabled=false; sub.textContent='Registrieren';
+        sub.disabled=false; sub.textContent=tr('registerBtn');
         errEl.textContent=err.message||'Fehler'; errEl.style.display='';
       });
   };
@@ -305,7 +491,7 @@ function openNew(){
   setTimeout(function(){name.focus();},50);
   c.querySelector('.ng-can').onclick=closeOv;
   sub.onclick=function(){
-    var nv=(name.value||'').trim(), uv=(unit.value||'').trim()||'Stück';
+    var nv=(name.value||'').trim(), uv=(unit.value||'').trim()||tr('unitDefault');
     var dv=parseFloat(daily.value)||1, dyv=parseInt(days.value,10)||30;
     if(!nv){ name.focus(); return; }
     sub.disabled=true;
@@ -316,7 +502,7 @@ function openNew(){
       }).catch(function(e){
         sub.disabled=false;
         if(e.status===401){ closeOv(); showLogin(); }
-        else showToast('Fehler beim Erstellen');
+        else showToast(tr('errCreate'));
       });
   };
 }
@@ -336,11 +522,11 @@ function openData(){
     nc.querySelector('.cn-can').onclick=closeOv;
     sub.onclick=function(){
       var nv=inp.value.trim();
-      if(!nv){ errEl.textContent='Name darf nicht leer sein'; errEl.style.display=''; return; }
+      if(!nv){ errEl.textContent=tr('errNameEmpty'); errEl.style.display=''; return; }
       sub.disabled=true; sub.textContent='…';
       api('PATCH','me',{name:nv})
-        .then(function(r){ userName=r.name; closeOv(); render(); showToast('Name gespeichert'); })
+        .then(function(r){ userName=r.name; closeOv(); render(); showToast(tr('nameSaved')); })
-        .catch(function(){ sub.disabled=false; sub.textContent='Speichern'; showToast('Fehler beim Speichern'); });
+        .catch(function(){ sub.disabled=false; sub.textContent=tr('save'); showToast(tr('errNameSave')); });
     };
   };
   c.querySelector('.dm-cpw').onclick=function(){ closeOv(); showChangePassword(); };
@@ -359,38 +545,38 @@ function openData(){
       btn.disabled=true; btn.textContent='…';
       api('POST','invite',{note:note}).then(function(res){
         var lc=tpl('tpl-invite-link');
-        lc.querySelector('.stitle').textContent='Einladungslink'+(note?' für '+note:'');
+        lc.querySelector('.stitle').textContent=tr('inviteLinkTitle')+(note?' — '+note:'');
         var urlInp=lc.querySelector('.il-url');
         urlInp.value=res.url;
         showSheet(lc,true);
         lc.querySelector('.il-close').onclick=closeOv;
         lc.querySelector('.il-copy').onclick=function(){
-          navigator.clipboard.writeText(res.url).then(function(){ showToast('Link kopiert!'); closeOv(); });
+          navigator.clipboard.writeText(res.url).then(function(){ showToast(tr('linkCopied')); closeOv(); });
         };
         setTimeout(function(){urlInp.select();},50);
       }).catch(function(){
-        btn.disabled=false; btn.textContent='Link generieren';
+        btn.disabled=false; btn.textContent=tr('generateLink');
-        showToast('Fehler beim Generieren');
+        showToast(tr('errGenerate'));
       });
     };
   };
 
   c.querySelector('.dm-invlist').onclick=function(){
     api('GET','invites').then(function(list){
-      var statusLabel={'pending':'Ausstehend','used':'Angenommen','expired':'Abgelaufen'};
+      var statusLabel={'pending':tr('statusPending'),'used':tr('statusUsed'),'expired':tr('statusExpired')};
       var statusColor={'pending':'var(--amber)','used':'var(--green)','expired':'var(--red)'};
       var lc=tpl('tpl-invite-list');
       var body=lc.querySelector('.dpanel-body');
       if(!list.length){
         var empty=document.createElement('div');
         empty.className='nosets'; empty.style.padding='16px';
-        empty.textContent='Noch keine Einladungen verschickt';
+        empty.textContent=tr('noInvites');
         body.appendChild(empty);
       } else {
         for(var i=0;i<list.length;i++){
           var inv=list[i];
-          var label=inv.note||new Date(inv.created_at).toLocaleDateString('de-DE',{day:'numeric',month:'short',year:'numeric'});
+          var label=inv.note||new Date(inv.created_at).toLocaleDateString(ldoc(),{day:'numeric',month:'short',year:'numeric'});
-          var detail=inv.used_by_email?('→ '+inv.used_by_email):(inv.status==='pending'?'läuft ab: '+new Date(inv.expires_at).toLocaleDateString('de-DE',{day:'numeric',month:'short'}):'');
+          var detail=inv.used_by_email?(tr('acceptedBy')+' '+inv.used_by_email):(inv.status==='pending'?tr('expiresAt')+' '+new Date(inv.expires_at).toLocaleDateString(ldoc(),{day:'numeric',month:'short'}):'');
           var row=tpl('tpl-invite-row');
           row.querySelector('.ir-label').textContent=label;
           if(detail) row.querySelector('.ir-detail').textContent=' '+detail;
@@ -398,14 +584,14 @@ function openData(){
           st.textContent=statusLabel[inv.status]; st.style.color=statusColor[inv.status];
           if(inv.url){
             var cp=row.querySelector('.ir-copy'); cp.style.display='';
-            cp.onclick=function(url){ return function(){ navigator.clipboard.writeText(url).then(function(){ showToast('Link kopiert!'); }); }; }(inv.url);
+            cp.onclick=function(url){ return function(){ navigator.clipboard.writeText(url).then(function(){ showToast(tr('linkCopied')); }); }; }(inv.url);
           }
           body.appendChild(row);
         }
       }
       showSheet(lc,true);
       lc.querySelector('.il-close').onclick=closeOv;
-    }).catch(function(){ showToast('Fehler beim Laden'); });
+    }).catch(function(){ showToast(tr('errLoad')); });
   };
 
   c.querySelector('.dm-exp').onclick=function(){
@@ -421,23 +607,28 @@ function openData(){
       var r=new FileReader(); r.onload=function(ev){
         try{
           var p=JSON.parse(ev.target.result);
-          if(!p.goals||!Array.isArray(p.goals)) throw new Error('Ungültiges Format');
+          if(!p.goals||!Array.isArray(p.goals)) throw new Error(tr('invalidFormat'));
-          if(!confirm(p.goals.length+' Ziel(e) importieren?')) return;
+          if(!confirm(tr('confirmImport').replace('{n}',p.goals.length))) return;
           var promises=p.goals.map(function(g){
             return api('POST','goals',{name:g.name,unit:g.unit,daily:g.daily,days:g.days,start:g.start,sets:g.sets||{}})
               .then(function(r){ goals.push({id:r.id,name:r.name,unit:r.unit,daily:r.daily,days:r.days,start:r.start,sets:r.sets||{}}); });
           });
-          Promise.all(promises).then(function(){ closeOv(); render(); alert(p.goals.length+' Ziel(e) importiert.'); });
+          Promise.all(promises).then(function(){ closeOv(); render(); alert(tr('importDone').replace('{n}',p.goals.length)); });
-        }catch(err){ alert('Fehler: '+err.message); }
+        }catch(err){ alert(err.message); }
       }; r.readAsText(f);
     }; inp.click();
   };
 
+  c.querySelectorAll('.btn-lang').forEach(function(b){
+    if(b.dataset.lang===LOCALE) b.classList.add('active');
+    b.onclick=function(){ setLocale(this.dataset.lang,true); closeOv(); };
+  });
+
   c.querySelector('.dm-clr').onclick=function(){
-    if(!confirm('Alle Daten löschen?')) return;
+    if(!confirm(tr('confirmClear'))) return;
     var ids=goals.map(function(g){return g.id;}); goals=[]; render();
     Promise.all(ids.map(function(id){return api('DELETE','goals/'+id);}))
-      .catch(function(){ showToast('Fehler beim Löschen'); });
+      .catch(function(){ showToast(tr('errDelete')); });
     closeOv();
   };
 }
@@ -459,7 +650,7 @@ function buildNameWrap(g){
 
 function buildPanel(g,off){
   var t=tOff(g), sets=g.sets[String(off)]||[], tot=dTot(g,off);
-  var lbl=off===t?'Heute':'Gestern', k=g.id+'_'+off;
+  var lbl=off===t?tr('heute'):tr('gestern'), k=g.id+'_'+off;
   var el=tpl('tpl-panel');
   el.querySelector('.dpanel-title').textContent=lbl+' — '+fd(o2d(g,off));
   el.querySelector('.dpanel-sub').textContent=tot+' / '+g.daily+' '+g.unit;
@@ -526,8 +717,8 @@ function buildCard(g){
   el.querySelector('.m-end').textContent=fs(c.end);
   var badge=el.querySelector('.badge'); badge.className='badge '+bc; badge.textContent=bt;
   var fill=el.querySelector('.prog-fill'); fill.style.width=c.pct+'%'; fill.style.background=fc;
-  el.querySelector('.pr-done').textContent=c.done+' '+g.unit+' gemacht';
+  el.querySelector('.pr-done').textContent=c.done+' '+g.unit+' '+tr('doneLabel');
-  el.querySelector('.pr-pct').textContent=c.pct+'% von '+c.tot;
+  el.querySelector('.pr-pct').textContent=c.pct+'% '+tr('ofLabel')+' '+c.tot;
   el.querySelector('.sv-tdone').textContent=c.tdone;
   el.querySelector('.sv-daily').textContent=g.daily;
   el.querySelector('.sv-st').textContent=c.st;
@@ -556,7 +747,7 @@ function buildQuickBook(){
   var active=goals.filter(function(g){ var c=calc(g); return tOff(g)<g.days&&!c.ok; });
   if(!active.length) return null;
   var frag=document.createDocumentFragment();
-  var lbl=document.createElement('div'); lbl.className='sec-lbl'; lbl.textContent='Quick-Buchen';
+  var lbl=document.createElement('div'); lbl.className='sec-lbl'; lbl.textContent=tr('qbLabel');
   frag.appendChild(lbl);
   var card=document.createElement('div'); card.className='card qb-card';
   for(var i=0;i<active.length;i++){
@@ -615,7 +806,7 @@ function render(){
   }
 
   if(userName){
-    var gr=document.createElement('div'); gr.className='greeting'; gr.textContent='Hallo '+userName+'!';
+    var gr=document.createElement('div'); gr.className='greeting'; gr.textContent=tr('hello').replace('{n}',userName);
     frag.appendChild(gr);
   }
 
@@ -627,12 +818,12 @@ function render(){
     if(c.ok) done.push(g); else open.push(g);
   }
   if(open.length){
-    var sl=document.createElement('div'); sl.className='sec-lbl'; sl.textContent='Offen';
+    var sl=document.createElement('div'); sl.className='sec-lbl'; sl.textContent=tr('openLabel');
     frag.appendChild(sl);
     for(var i=0;i<open.length;i++) frag.appendChild(buildCard(open[i]));
   }
   if(done.length){
-    var sl2=document.createElement('div'); sl2.className='sec-lbl'; sl2.textContent='Heute erledigt';
+    var sl2=document.createElement('div'); sl2.className='sec-lbl'; sl2.textContent=tr('doneToday');
     frag.appendChild(sl2);
     for(var j=0;j<done.length;j++) frag.appendChild(buildCard(done[j]));
   }
@@ -678,7 +869,7 @@ function wire(){
 // ── Start ─────────────────────────────────────────────────────────────────────
 
 function updateHeader(){
-  document.getElementById('tlbl').textContent=TODAY.toLocaleDateString('de-DE',{weekday:'long',day:'numeric',month:'long'});
+  document.getElementById('tlbl').textContent=TODAY.toLocaleDateString(ldoc(),{weekday:'long',day:'numeric',month:'long'});
 }
 
 document.getElementById('btnNew').onclick=openNew;
@@ -691,14 +882,23 @@ var resetSelector=_qs.get('reset_selector');
 var resetToken=_qs.get('reset_token');
 if(inviteToken||resetSelector) history.replaceState(null,'',location.pathname);
 
+function applyLocale(userLocale){
+  var lang = userLocale || localStorage.getItem('zt_locale');
+  if(!lang){
+    var nav = (navigator.language||'').slice(0,2).toLowerCase();
+    if(STRINGS[nav]) lang = nav;
+  }
+  if(lang && STRINGS[lang]) LOCALE = lang;
+}
+
 if(resetSelector&&resetToken){
-  render(); showResetPassword(resetSelector,resetToken);
+  applyLocale(null); render(); showResetPassword(resetSelector,resetToken);
 } else {
   api('GET','me')
-    .then(function(r){ userName=r.name||''; updateHeader(); return loadGoals(); })
+    .then(function(r){ userName=r.name||''; applyLocale(r.locale); updateHeader(); return loadGoals(); })
     .then(function(g){ goals=g; render(); })
     .catch(function(){
-      render();
+      applyLocale(null); render();
       if(inviteToken){ showRegister(inviteToken); }
       else { showLogin(); }
     });

public/style.css

@@ -115,3 +115,6 @@ body{font-family:'DM Sans',sans-serif;background:var(--bg);color:var(--text);min
 .hint{margin:0 16px 12px;background:var(--blue-bg);border:1px solid rgba(37,99,235,.15);border-radius:var(--rs);padding:10px 12px;font-size:12px;color:var(--blue);line-height:1.5;display:flex;justify-content:space-between;align-items:center;gap:8px}
 .hclose{background:none;border:none;color:var(--blue);cursor:pointer;font-size:16px;padding:0 2px}
 .btn-lnk{background:none;border:none;color:var(--text2);font-size:13px;cursor:pointer;padding:4px 8px;text-decoration:underline;text-underline-offset:2px}
+.lang-row{display:flex;gap:8px;margin-bottom:8px}
+.btn-lang{flex:1;padding:8px;border-radius:var(--rs);background:var(--bg3);color:var(--text2);border:1px solid var(--border);cursor:pointer;font-family:'DM Mono',monospace;font-size:13px;font-weight:600;letter-spacing:.5px}
+.btn-lang.active{background:var(--text);color:var(--bg);border-color:var(--text)}

src/Controller/AuthController.php

@@ -32,10 +32,11 @@ class AuthController extends AbstractController
             return new JsonResponse(['ok' => false], Response::HTTP_UNAUTHORIZED);
         }
         return new JsonResponse([
-            'ok'    => true,
+            'ok'     => true,
-            'email' => $user->getEmail(),
+            'email'  => $user->getEmail(),
-            'id'    => $user->getId(),
+            'id'     => $user->getId(),
-            'name'  => $user->getUsername() ?? '',
+            'name'   => $user->getUsername() ?? '',
+            'locale' => $user->getLocale(),
         ]);
     }
 
@@ -47,6 +48,18 @@ class AuthController extends AbstractController
             return new JsonResponse(['error' => 'Unauthorized'], Response::HTTP_UNAUTHORIZED);
         }
         $data = json_decode($request->getContent(), true) ?? [];
+        $allowed = ['de', 'en', 'pl'];
+
+        if (isset($data['locale'])) {
+            $locale = $data['locale'];
+            if (!in_array($locale, $allowed, true)) {
+                return new JsonResponse(['error' => 'Ungültige Sprache'], Response::HTTP_BAD_REQUEST);
+            }
+            $user->setLocale($locale);
+            $this->em->flush();
+            return new JsonResponse(['ok' => true, 'locale' => $locale]);
+        }
+
         $name = trim($data['name'] ?? '');
         if (!$name) {
             return new JsonResponse(['error' => 'Name fehlt'], Response::HTTP_BAD_REQUEST);

src/Entity/User.php

@@ -34,6 +34,9 @@ class User implements UserInterface, PasswordAuthenticatedUserInterface
     #[ORM\Column(type: 'integer', nullable: true, options: ['unsigned' => true])]
     private ?int $lastLogin = null;
 
+    #[ORM\Column(length: 2, nullable: true)]
+    private ?string $locale = null;
+
     public function __construct()
     {
         $this->registered = time();
@@ -51,6 +54,8 @@ class User implements UserInterface, PasswordAuthenticatedUserInterface
     public function getRegistered(): int { return $this->registered; }
     public function getLastLogin(): ?int { return $this->lastLogin; }
     public function setLastLogin(?int $lastLogin): static { $this->lastLogin = $lastLogin; return $this; }
+    public function getLocale(): ?string { return $this->locale; }
+    public function setLocale(?string $locale): static { $this->locale = $locale; return $this; }
 
     // UserInterface
     public function getUserIdentifier(): string { return $this->email; }

templates/app.html.twig

@@ -29,11 +29,11 @@
 <!-- ── Templates ──────────────────────────────────────────────────────────── -->
 
 <template id="tpl-hint">
-  <div class="hint">Menü → "Zum Startbildschirm" für App-Icon<button class="hclose">×</button></div>
+  <div class="hint"><span data-t="hint"></span><button class="hclose">×</button></div>
 </template>
 
 <template id="tpl-empty">
-  <div class="empty"><div style="font-size:40px;opacity:.4;margin-bottom:12px">🎯</div>Noch keine Ziele.<br>Tippe auf <strong>+</strong> um zu starten.</div>
+  <div class="empty"><div style="font-size:40px;opacity:.4;margin-bottom:12px">🎯</div><span data-t="emptyLine1"></span><br><span data-t="emptyLine2"></span></div>
 </template>
 
 <template id="tpl-dot">
@@ -41,7 +41,7 @@
 </template>
 
 <template id="tpl-nosets">
-  <div class="nosets">Noch kein Eintrag</div>
+  <div class="nosets" data-t="noEntry"></div>
 </template>
 
 <template id="tpl-set-row">
@@ -56,7 +56,7 @@
     <input class="num-in" type="number" min="1"/>
     <span class="ulbl"></span>
     <button class="btn-sw-fill" style="display:none">⏱</button>
-    <button class="btn-as">Eintragen</button>
+    <button class="btn-as" data-t="log"></button>
   </div>
 </template>
 
@@ -76,7 +76,7 @@
     <div class="qb-stat"></div>
     <input class="num-in" type="number" min="1"/>
     <button class="btn-sw-fill" style="display:none">⏱</button>
-    <button class="btn-as">Eintragen</button>
+    <button class="btn-as" data-t="log"></button>
   </div>
 </template>
 
@@ -97,7 +97,7 @@
   <div class="card">
     <div class="card-hdr">
       <div class="card-bd" style="flex:1;min-width:0">
-        <div class="goal-meta">Noch <span class="m-dr"></span>T · endet <span class="m-end"></span> · heute: <span class="m-heute"></span><br>total: <span class="m-total"></span></div>
+        <div class="goal-meta"><span data-t="noch"></span> <span class="m-dr"></span><span data-t="dAbbr"></span> · <span data-t="endet"></span> <span class="m-end"></span> · <span data-t="todayShort"></span>: <span class="m-heute"></span><br><span data-t="total"></span>: <span class="m-total"></span></div>
       </div>
       <span class="badge"></span>
       <span class="chevron">▸</span>
@@ -112,7 +112,7 @@
   <div class="card">
     <div class="card-hdr">
       <div class="card-bd" style="flex:1;min-width:0">
-        <div class="goal-meta">Noch <span class="m-dr"></span>T · endet <span class="m-end"></span></div>
+        <div class="goal-meta"><span data-t="noch"></span> <span class="m-dr"></span><span data-t="dAbbr"></span> · <span data-t="endet"></span> <span class="m-end"></span></div>
       </div>
       <span class="badge"></span>
       <span class="chevron">▴</span>
@@ -126,34 +126,34 @@
     </div>
     <div class="heute-stats">
       <div class="heute-group">
-        <div class="heute-lbl">Heute</div>
+        <div class="heute-lbl" data-t="todayHeading"></div>
         <div class="heute-inner">
           <div class="stat">
-            <div class="slbl">Gemacht</div>
+            <div class="slbl" data-t="done2"></div>
             <div class="sval"><span class="sv-tdone"></span><div class="sunit"></div></div>
           </div>
           <div class="stat">
-            <div class="slbl">Tagesziel</div>
+            <div class="slbl" data-t="dailyGoal"></div>
             <div class="sval"><span class="sv-daily"></span><div class="sunit"></div></div>
           </div>
           <div class="stat">
-            <div class="slbl">Noch</div>
+            <div class="slbl" data-t="remaining"></div>
             <div class="sval sv-noch"><span class="sv-st"></span><div class="sunit"></div></div>
           </div>
         </div>
       </div>
     </div>
     <div class="dots-sec">
-      <div class="dots-lbl">Verlauf — heute &amp; gestern bearbeitbar</div>
+      <div class="dots-lbl" data-t="history"></div>
       <div class="dots-wrap"></div>
       <div class="legend">
-        <span class="leg"><span class="ldot" style="background:rgba(37,99,235,.3)"></span>Puffer</span>
+        <span class="leg"><span class="ldot" style="background:rgba(37,99,235,.3)"></span><span data-t="legBuf"></span></span>
-        <span class="leg"><span class="ldot" style="background:rgba(22,163,74,.3)"></span>Erreicht</span>
+        <span class="leg"><span class="ldot" style="background:rgba(22,163,74,.3)"></span><span data-t="legDone"></span></span>
-        <span class="leg"><span class="ldot" style="background:rgba(217,119,6,.3)"></span>Teilweise</span>
+        <span class="leg"><span class="ldot" style="background:rgba(217,119,6,.3)"></span><span data-t="legPartial"></span></span>
-        <span class="leg"><span class="ldot" style="background:rgba(220,38,38,.3)"></span>Verpasst</span>
+        <span class="leg"><span class="ldot" style="background:rgba(220,38,38,.3)"></span><span data-t="legMissed"></span></span>
       </div>
     </div>
-    <div class="card-foot"><button class="btn-del">Ziel löschen</button></div>
+    <div class="card-foot"><button class="btn-del" data-t="delGoal"></button></div>
   </div>
 </template>
 
@@ -165,139 +165,145 @@
 
 <template id="tpl-login">
   <div>
-    <div class="stitle">Anmelden</div>
+    <div class="stitle" data-t="loginTitle"></div>
     <div class="ssub">Dudi</div>
     <div class="login-err" style="display:none"></div>
-    <div class="ff"><label>E-Mail</label><input class="fi lf-email" type="email" autocomplete="email"/></div>
+    <div class="ff"><label data-t="emailLabel"></label><input class="fi lf-email" type="email" autocomplete="email"/></div>
-    <div class="ff"><label>Passwort</label><input class="fi lf-pass" type="password" autocomplete="current-password"/></div>
+    <div class="ff"><label data-t="passwordLabel"></label><input class="fi lf-pass" type="password" autocomplete="current-password"/></div>
-    <div class="factions"><button class="btn-p lf-sub">Anmelden</button></div>
+    <div class="factions"><button class="btn-p lf-sub" data-t="loginBtn"></button></div>
-    <div style="text-align:center;margin-top:8px"><button class="btn-lnk lf-fgt">Passwort vergessen?</button></div>
+    <div style="text-align:center;margin-top:8px"><button class="btn-lnk lf-fgt" data-t="forgotPw"></button></div>
   </div>
 </template>
 
 <template id="tpl-forgot-pw">
   <div>
-    <div class="stitle">Passwort vergessen</div>
+    <div class="stitle" data-t="forgotTitle"></div>
-    <div class="ssub">Wir schicken dir einen Reset-Link</div>
+    <div class="ssub" data-t="forgotSub"></div>
-    <div class="ff"><label>E-Mail</label><input class="fi fp-email" type="email" autocomplete="email"/></div>
+    <div class="ff"><label data-t="emailLabel"></label><input class="fi fp-email" type="email" autocomplete="email"/></div>
     <div class="login-err" style="display:none"></div>
     <div class="factions">
-      <button class="btn-p fp-sub">Link senden</button>
+      <button class="btn-p fp-sub" data-t="sendLink"></button>
-      <button class="btn-c fp-back">Zurück</button>
+      <button class="btn-c fp-back" data-t="back"></button>
     </div>
   </div>
 </template>
 
 <template id="tpl-email-sent">
   <div>
-    <div class="stitle">E-Mail gesendet</div>
+    <div class="stitle" data-t="emailSentTitle"></div>
-    <div class="ssub">Falls die Adresse bekannt ist, erhältst du in Kürze einen Reset-Link.</div>
+    <div class="ssub" data-t="emailSentSub"></div>
-    <div class="factions"><button class="btn-p es-ok">OK</button></div>
+    <div class="factions"><button class="btn-p es-ok" data-t="ok"></button></div>
   </div>
 </template>
 
 <template id="tpl-reset-pw">
   <div>
-    <div class="stitle">Neues Passwort</div>
+    <div class="stitle" data-t="resetTitle"></div>
-    <div class="ff"><label>Neues Passwort</label><input class="fi rp-pass" type="password" autocomplete="new-password" placeholder="mind. 8 Zeichen"/></div>
+    <div class="ff"><label data-t="newPwLabel"></label><input class="fi rp-pass" type="password" autocomplete="new-password" data-ph="min8"/></div>
     <div class="login-err" style="display:none"></div>
-    <div class="factions"><button class="btn-p rp-sub">Passwort setzen</button></div>
+    <div class="factions"><button class="btn-p rp-sub" data-t="setPw"></button></div>
   </div>
 </template>
 
 <template id="tpl-pw-changed">
   <div>
-    <div class="stitle">Passwort geändert</div>
+    <div class="stitle" data-t="pwChangedTitle"></div>
-    <div class="ssub">Du kannst dich jetzt anmelden.</div>
+    <div class="ssub" data-t="pwChangedSub"></div>
-    <div class="factions"><button class="btn-p pc-ok">Anmelden</button></div>
+    <div class="factions"><button class="btn-p pc-ok" data-t="loginBtn"></button></div>
   </div>
 </template>
 
 <template id="tpl-change-name">
   <div>
-    <div class="stitle">Name ändern</div>
+    <div class="stitle" data-t="changeNameTitle"></div>
-    <div class="ff"><label>Dein Name</label><input class="fi cn-name" type="text" autocomplete="name"/></div>
+    <div class="ff"><label data-t="yourName"></label><input class="fi cn-name" type="text" autocomplete="name"/></div>
     <div class="login-err" style="display:none"></div>
     <div class="factions">
-      <button class="btn-p cn-sub">Speichern</button>
+      <button class="btn-p cn-sub" data-t="save"></button>
-      <button class="btn-c cn-can">Abbrechen</button>
+      <button class="btn-c cn-can" data-t="cancel"></button>
     </div>
   </div>
 </template>
 
 <template id="tpl-change-pw">
   <div>
-    <div class="stitle">Passwort ändern</div>
+    <div class="stitle" data-t="changePwTitle"></div>
-    <div class="ff"><label>Aktuelles Passwort</label><input class="fi cp-old" type="password" autocomplete="current-password"/></div>
+    <div class="ff"><label data-t="currentPwLabel"></label><input class="fi cp-old" type="password" autocomplete="current-password"/></div>
-    <div class="ff"><label>Neues Passwort</label><input class="fi cp-new" type="password" autocomplete="new-password" placeholder="mind. 8 Zeichen"/></div>
+    <div class="ff"><label data-t="newPwLabel"></label><input class="fi cp-new" type="password" autocomplete="new-password" data-ph="min8"/></div>
-    <div class="ff"><label>Neues Passwort bestätigen</label><input class="fi cp-new2" type="password" autocomplete="new-password" placeholder="mind. 8 Zeichen"/></div>
+    <div class="ff"><label data-t="newPwConfLabel"></label><input class="fi cp-new2" type="password" autocomplete="new-password" data-ph="min8"/></div>
     <div class="login-err" style="display:none"></div>
     <div class="factions">
-      <button class="btn-p cp-sub">Ändern</button>
+      <button class="btn-p cp-sub" data-t="changePwBtn"></button>
-      <button class="btn-c cp-can">Abbrechen</button>
+      <button class="btn-c cp-can" data-t="cancel"></button>
     </div>
   </div>
 </template>
 
 <template id="tpl-register">
   <div>
-    <div class="stitle">Konto erstellen</div>
+    <div class="stitle" data-t="registerTitle"></div>
-    <div class="ssub">Du wurdest eingeladen</div>
+    <div class="ssub" data-t="registerSub"></div>
-    <div class="ff"><label>Dein Name</label><input class="fi rg-name" type="text" autocomplete="name" placeholder="Wie sollen wir dich nennen?"/></div>
+    <div class="ff"><label data-t="yourName"></label><input class="fi rg-name" type="text" autocomplete="name" data-ph="namePlaceholder"/></div>
-    <div class="ff"><label>E-Mail</label><input class="fi rg-email" type="email" autocomplete="email"/></div>
+    <div class="ff"><label data-t="emailLabel"></label><input class="fi rg-email" type="email" autocomplete="email"/></div>
-    <div class="ff"><label>Passwort</label><input class="fi rg-pass" type="password" autocomplete="new-password" placeholder="mind. 8 Zeichen"/></div>
+    <div class="ff"><label data-t="passwordLabel"></label><input class="fi rg-pass" type="password" autocomplete="new-password" data-ph="min8"/></div>
-    <div class="ff"><label>Passwort bestätigen</label><input class="fi rg-pass2" type="password" autocomplete="new-password" placeholder="Passwort wiederholen"/></div>
+    <div class="ff"><label data-t="pwConfLabel"></label><input class="fi rg-pass2" type="password" autocomplete="new-password" data-ph="pwPlaceholder"/></div>
     <div class="login-err" style="display:none"></div>
-    <div class="factions"><button class="btn-p rg-sub">Registrieren</button></div>
+    <div class="factions"><button class="btn-p rg-sub" data-t="registerBtn"></button></div>
   </div>
 </template>
 
 <template id="tpl-new-goal">
   <div>
-    <div class="stitle">Neues Ziel</div>
+    <div class="stitle" data-t="newGoalTitle"></div>
-    <div class="ff"><label>Übung / Gewohnheit</label><input class="fi ng-name" type="text" placeholder="Liegestütz, Plank …"/></div>
+    <div class="ff"><label data-t="exerciseLabel"></label><input class="fi ng-name" type="text" data-ph="exercisePlaceholder"/></div>
     <div class="fgrid">
-      <div class="ff"><label>Einheit</label><input class="fi ng-unit" type="text" value="Stück"/></div>
+      <div class="ff"><label data-t="unitLabel"></label><input class="fi ng-unit" type="text" data-val="unitDefault"/></div>
-      <div class="ff"><label>Dauer in Tagen</label><input class="fi ng-days" type="number" min="7" max="365" value="30"/></div>
+      <div class="ff"><label data-t="daysLabel"></label><input class="fi ng-days" type="number" min="7" max="365" value="30"/></div>
     </div>
     <div class="fgrid">
-      <div class="ff"><label>Tagesziel</label><input class="fi ng-daily" type="number" min="0.01" step="any" value="50"/></div>
+      <div class="ff"><label data-t="dailyLabel"></label><input class="fi ng-daily" type="number" min="0.01" step="any" value="50"/></div>
-      <div class="ff"><label>Wochenziel</label><input class="fi ng-weekly" type="number" min="0.01" step="any" value="350"/></div>
+      <div class="ff"><label data-t="weeklyLabel"></label><input class="fi ng-weekly" type="number" min="0.01" step="any" value="350"/></div>
     </div>
     <div class="factions">
-      <button class="btn-p ng-sub">Ziel starten</button>
+      <button class="btn-p ng-sub" data-t="startGoal"></button>
-      <button class="btn-c ng-can">Abbrechen</button>
+      <button class="btn-c ng-can" data-t="cancel"></button>
     </div>
   </div>
 </template>
 
 <template id="tpl-data-menu">
   <div>
-    <div class="stitle">Daten verwalten</div>
+    <div class="stitle" data-t="dataMenuTitle"></div>
-    <div class="ssub">Export, Import und Backup</div>
+    <div class="ssub" data-t="dataMenuSub"></div>
-    <button class="dbtn dm-exp"><span class="dico">⬇</span><span class="dlbl">Exportieren<span class="dsub">Alle Ziele als JSON-Datei speichern</span></span></button>
+    <button class="dbtn dm-exp"><span class="dico">⬇</span><span class="dlbl"><span data-t="exportLabel"></span><span class="dsub" data-t="exportSub"></span></span></button>
-    <button class="dbtn dm-imp"><span class="dico">⬆</span><span class="dlbl">Importieren<span class="dsub">Backup laden oder zusammenführen</span></span></button>
+    <button class="dbtn dm-imp"><span class="dico">⬆</span><span class="dlbl"><span data-t="importLabel"></span><span class="dsub" data-t="importSub"></span></span></button>
     <div class="ddiv"></div>
-    <button class="dbtn dm-inv"><span class="dico">🔗</span><span class="dlbl">Freund einladen<span class="dsub">Einladungslink generieren</span></span></button>
+    <button class="dbtn dm-inv"><span class="dico">🔗</span><span class="dlbl"><span data-t="inviteLabel"></span><span class="dsub" data-t="inviteSub"></span></span></button>
-    <button class="dbtn dm-invlist"><span class="dico">📋</span><span class="dlbl">Meine Einladungen<span class="dsub">Status aller gesendeten Einladungen</span></span></button>
+    <button class="dbtn dm-invlist"><span class="dico">📋</span><span class="dlbl"><span data-t="inviteListLabel"></span><span class="dsub" data-t="inviteListSub"></span></span></button>
     <div class="ddiv"></div>
-    <button class="dbtn dm-name"><span class="dico">✏️</span><span class="dlbl">Name ändern</span></button>
+    <button class="dbtn dm-name"><span class="dico">✏️</span><span class="dlbl" data-t="changeName"></span></button>
-    <button class="dbtn dm-cpw"><span class="dico">🔑</span><span class="dlbl">Passwort ändern</span></button>
+    <button class="dbtn dm-cpw"><span class="dico">🔑</span><span class="dlbl" data-t="changePw"></span></button>
-    <button class="dbtn dm-lgout"><span class="dico">→</span><span class="dlbl">Abmelden</span></button>
+    <button class="dbtn dm-lgout"><span class="dico">→</span><span class="dlbl" data-t="logout"></span></button>
-    <button class="btn-c dm-cls" style="width:100%;margin-top:4px;text-align:center">Schließen</button>
+    <div class="ddiv"></div>
+    <div class="lang-row">
+      <button class="btn-lang" data-lang="de">DE</button>
+      <button class="btn-lang" data-lang="en">EN</button>
+      <button class="btn-lang" data-lang="pl">PL</button>
+    </div>
+    <button class="btn-c dm-cls" style="width:100%;margin-top:4px;text-align:center" data-t="close"></button>
     <div class="ddiv" style="margin-top:16px"></div>
-    <button class="dbtn ddanger dm-clr"><span class="dico">✕</span><span class="dlbl">Alle Daten löschen<span class="dsub">Kann nicht rückgängig gemacht werden</span></span></button>
+    <button class="dbtn ddanger dm-clr"><span class="dico">✕</span><span class="dlbl"><span data-t="clearAll"></span><span class="dsub" data-t="clearAllSub"></span></span></button>
   </div>
 </template>
 
 <template id="tpl-invite-form">
   <div>
-    <div class="stitle">Freund einladen</div>
+    <div class="stitle" data-t="inviteFormTitle"></div>
-    <div class="ssub">Link gilt 7 Tage und kann nur einmal verwendet werden</div>
+    <div class="ssub" data-t="inviteFormSub"></div>
-    <div class="ff"><label>Name (für deine Übersicht)</label><input class="fi inv-name" type="text" placeholder="z.B. Max"/></div>
+    <div class="ff"><label data-t="inviteNameLabel"></label><input class="fi inv-name" type="text" data-ph="inviteNamePlaceholder"/></div>
     <div class="factions">
-      <button class="btn-p inv-gen">Link generieren</button>
+      <button class="btn-p inv-gen" data-t="generateLink"></button>
-      <button class="btn-c inv-cancel">Abbrechen</button>
+      <button class="btn-c inv-cancel" data-t="cancel"></button>
     </div>
   </div>
 </template>
@@ -305,27 +311,27 @@
 <template id="tpl-invite-link">
   <div>
     <div class="stitle"></div>
-    <div class="ssub">Link gilt 7 Tage und kann nur einmal verwendet werden</div>
+    <div class="ssub" data-t="inviteFormSub"></div>
     <div class="ff"><input class="fi il-url" type="text" readonly/></div>
     <div class="factions">
-      <button class="btn-p il-copy">Link kopieren</button>
+      <button class="btn-p il-copy" data-t="copyLink"></button>
-      <button class="btn-c il-close">Schließen</button>
+      <button class="btn-c il-close" data-t="close"></button>
     </div>
   </div>
 </template>
 
 <template id="tpl-invite-list">
   <div>
-    <div class="stitle">Meine Einladungen</div>
+    <div class="stitle" data-t="inviteListLabel"></div>
     <div class="dpanel-body"></div>
-    <div class="factions"><button class="btn-c il-close">Schließen</button></div>
+    <div class="factions"><button class="btn-c il-close" data-t="close"></button></div>
   </div>
 </template>
 
 <template id="tpl-invite-row">
   <div class="set-row">
     <span style="flex:1"><strong class="ir-label"></strong><span class="ir-detail" style="opacity:.6;font-size:.85em"></span></span>
-    <button class="ir-copy btn-lnk" style="font-size:.8em;display:none">🔗 Link</button>
+    <button class="ir-copy btn-lnk" style="font-size:.8em;display:none">🔗 <span data-t="linkLabel"></span></button>
     <span class="ir-status" style="font-size:.85em;font-weight:600"></span>
   </div>
 </template>