Add i18n support for French and German with browser language detection

app.py

@@ -7,6 +7,7 @@ from flask import Flask
 from models import init_db
 from auth import auth_bp
 from meals import meals_bp
+from i18n import init_i18n
 
 
 def create_app() -> Flask:
@@ -19,6 +20,8 @@ def create_app() -> Flask:
     with app.app_context():
         init_db()
 
+    init_i18n(app)
+
     return app
 
 

auth.py

@@ -12,6 +12,7 @@ from models import (
     get_all_households,
     count_household_users,
 )
+from i18n import t
 
 auth_bp = Blueprint("auth", __name__)
 
@@ -23,12 +24,12 @@ def login():
         password = request.form.get("password", "")
 
         if not username or not password:
-            flash("Username and password are required.", "error")
+            flash(t("Username and password are required."), "error")
             return render_template("login.html")
 
         user = get_user_by_username(username)
         if user is None or not check_password_hash(user["password_hash"], password):
-            flash("Invalid username or password.", "error")
+            flash(t("Invalid username or password."), "error")
             return render_template("login.html")
 
         household_id = user["household_id"]
@@ -59,32 +60,32 @@ def register():
 
         errors = []
         if not username or len(username) < 2:
-            errors.append("Username must be at least 2 characters.")
+            errors.append(t("Username must be at least 2 characters."))
         if not password or len(password) < 4:
-            errors.append("Password must be at least 4 characters.")
+            errors.append(t("Password must be at least 4 characters."))
         if password != confirm:
-            errors.append("Passwords do not match.")
+            errors.append(t("Passwords do not match."))
         if get_user_by_username(username):
-            errors.append("Username already taken.")
+            errors.append(t("Username already taken."))
 
         target_household_id = None
 
         if household_action == "create":
             if not new_household_name:
-                errors.append("Household name is required.")
+                errors.append(t("Household name is required."))
             elif get_household_by_name(new_household_name):
-                errors.append("A household with that name already exists.")
+                errors.append(t("A household with that name already exists."))
             else:
                 household = create_household(new_household_name)
                 target_household_id = household["id"]
                 is_admin = True  # First user in a new household is admin
         else:
             if not household_id:
-                errors.append("Please select a household.")
+                errors.append(t("Please select a household."))
             else:
                 hh = get_household_by_id(int(household_id))
                 if hh is None:
-                    errors.append("Selected household does not exist.")
+                    errors.append(t("Selected household does not exist."))
                 else:
                     target_household_id = hh["id"]
                     is_admin = False
@@ -104,7 +105,7 @@ def register():
         session["household_id"] = user["household_id"]
         session["household_name"] = get_household_by_id(target_household_id)["name"]
 
-        flash("Account created! Welcome to your household.", "success")
+        flash(t("Account created! Welcome to your household."), "success")
         return redirect(url_for("meals.dashboard"))
 
     return render_template("register.html", households=households)

i18n.py

@@ -0,0 +1,401 @@
+"""Lightweight i18n — French and German translations, browser-language detection."""
+
+from __future__ import annotations
+
+from flask import request, session, g
+
+# ── Supported languages ───────────────────────────────────────────────────────
+LANGUAGES = {
+    "en": "English",
+    "fr": "Français",
+    "de": "Deutsch",
+}
+
+FALLBACK = "en"
+
+
+# ── Translations ──────────────────────────────────────────────────────────────
+# Keys are English strings; values are dicts of language → translated string.
+# Only non-English translations are stored; English is the key itself.
+
+TRANSLATIONS: dict[str, dict[str, str]] = {
+    # ── base.html ──
+    "Meal Tracker": {
+        "fr": "Suivi des Repas",
+        "de": "Mahlzeiten-Tracker",
+    },
+    "admin": {
+        "fr": "administrateur",
+        "de": "Administrator",
+    },
+    "Logout": {
+        "fr": "Déconnexion",
+        "de": "Abmelden",
+    },
+
+    # ── login.html ──
+    "Log In": {
+        "fr": "Se connecter",
+        "de": "Anmelden",
+    },
+    "Username": {
+        "fr": "Nom d'utilisateur",
+        "de": "Benutzername",
+    },
+    "Password": {
+        "fr": "Mot de passe",
+        "de": "Passwort",
+    },
+    "Don't have an account?": {
+        "fr": "Pas de compte ?",
+        "de": "Kein Konto?",
+    },
+    "Register": {
+        "fr": "S'inscrire",
+        "de": "Registrieren",
+    },
+
+    # ── register.html ──
+    "Create Account": {
+        "fr": "Créer un compte",
+        "de": "Konto erstellen",
+    },
+    "Confirm Password": {
+        "fr": "Confirmer le mot de passe",
+        "de": "Passwort bestätigen",
+    },
+    "Household": {
+        "fr": "Foyer",
+        "de": "Haushalt",
+    },
+    "Join an existing household": {
+        "fr": "Rejoindre un foyer existant",
+        "de": "Einem bestehenden Haushalt beitreten",
+    },
+    "— Select —": {
+        "fr": "— Sélectionner —",
+        "de": "— Auswählen —",
+    },
+    "No households yet. Create one below!": {
+        "fr": "Pas encore de foyer. Créez-en un ci-dessous !",
+        "de": "Noch keine Haushalte. Erstellen Sie unten einen!",
+    },
+    "Create a new household": {
+        "fr": "Créer un nouveau foyer",
+        "de": "Neuen Haushalt erstellen",
+    },
+    "Household name (e.g. The Smiths)": {
+        "fr": "Nom du foyer (ex. Les Dupont)",
+        "de": "Haushaltsname (z.B. Familie Müller)",
+    },
+    "You'll be the admin of this household.": {
+        "fr": "Vous serez l'administrateur de ce foyer.",
+        "de": "Sie werden der Administrator dieses Haushalts sein.",
+    },
+    "Already have an account?": {
+        "fr": "Vous avez déjà un compte ?",
+        "de": "Haben Sie bereits ein Konto?",
+    },
+    "Log in": {
+        "fr": "Se connecter",
+        "de": "Anmelden",
+    },
+
+    # ── dashboard.html ──
+    "Today's Meals": {
+        "fr": "Repas du jour",
+        "de": "Heutige Mahlzeiten",
+    },
+    "History — {date}": {
+        "fr": "Historique — {date}",
+        "de": "Verlauf — {date}",
+    },
+    "◀ Prev": {
+        "fr": "◀ Préc.",
+        "de": "◀ Zurück",
+    },
+    "Next ▶": {
+        "fr": "Suiv. ▶",
+        "de": "Weiter ▶",
+    },
+    "Today": {
+        "fr": "Aujourd'hui",
+        "de": "Heute",
+    },
+    "No registered users yet. Ask household members to register!": {
+        "fr": "Pas encore d'utilisateurs. Invitez les membres du foyer à s'inscrire !",
+        "de": "Noch keine registrierten Benutzer. Bitten Sie Haushaltsmitglieder, sich zu registrieren!",
+    },
+    "User": {
+        "fr": "Utilisateur",
+        "de": "Benutzer",
+    },
+    "Lunch": {
+        "fr": "Déjeuner",
+        "de": "Mittagessen",
+    },
+    "Dinner": {
+        "fr": "Dîner",
+        "de": "Abendessen",
+    },
+    "you": {
+        "fr": "vous",
+        "de": "du",
+    },
+    "Home": {
+        "fr": "Présent",
+        "de": "Zuhause",
+    },
+    "Out": {
+        "fr": "Absent",
+        "de": "Auswärts",
+    },
+    "—": {
+        "fr": "—",
+        "de": "—",
+    },
+    "Remove": {
+        "fr": "Retirer",
+        "de": "Entfernen",
+    },
+    "Changed mind at {time}": {
+        "fr": "A changé d'avis à {time}",
+        "de": "Meinung geändert um {time}",
+    },
+    "⚙ Account Settings": {
+        "fr": "⚙ Paramètres du compte",
+        "de": "⚙ Kontoeinstellungen",
+    },
+    "Delete My Account": {
+        "fr": "Supprimer mon compte",
+        "de": "Mein Konto löschen",
+    },
+    "Enter your password to confirm": {
+        "fr": "Entrez votre mot de passe pour confirmer",
+        "de": "Geben Sie Ihr Passwort zur Bestätigung ein",
+    },
+    "Delete Household": {
+        "fr": "Supprimer le foyer",
+        "de": "Haushalt löschen",
+    },
+    "This will remove all users and all data in this household.": {
+        "fr": "Cela supprimera tous les utilisateurs et toutes les données de ce foyer.",
+        "de": "Dies entfernt alle Benutzer und alle Daten in diesem Haushalt.",
+    },
+
+    # ── JS confirm strings ──
+    "Delete YOUR account? This cannot be undone.": {
+        "fr": "Supprimer VOTRE compte ? Cette action est irréversible.",
+        "de": "IHR Konto löschen? Dies kann nicht rückgängig gemacht werden.",
+    },
+    "Remove {name} from this household?": {
+        "fr": "Retirer {name} de ce foyer ?",
+        "de": "{name} aus diesem Haushalt entfernen?",
+    },
+    "Delete the ENTIRE household and ALL members? This cannot be undone.": {
+        "fr": "Supprimer le foyer ENTIER et TOUS ses membres ? Cette action est irréversible.",
+        "de": "Den GESAMTEN Haushalt und ALLE Mitglieder löschen? Dies kann nicht rückgängig gemacht werden.",
+    },
+
+    # ── Page titles ──
+    "Login — Meal Tracker": {
+        "fr": "Connexion — Suivi des Repas",
+        "de": "Anmeldung — Mahlzeiten-Tracker",
+    },
+    "Register — Meal Tracker": {
+        "fr": "Inscription — Suivi des Repas",
+        "de": "Registrierung — Mahlzeiten-Tracker",
+    },
+    "Dashboard — Meal Tracker": {
+        "fr": "Tableau de bord — Suivi des Repas",
+        "de": "Übersicht — Mahlzeiten-Tracker",
+    },
+
+    # ── Flash / error messages ──
+    "Username and password are required.": {
+        "fr": "Le nom d'utilisateur et le mot de passe sont requis.",
+        "de": "Benutzername und Passwort sind erforderlich.",
+    },
+    "Invalid username or password.": {
+        "fr": "Nom d'utilisateur ou mot de passe invalide.",
+        "de": "Ungültiger Benutzername oder Passwort.",
+    },
+    "Username must be at least 2 characters.": {
+        "fr": "Le nom d'utilisateur doit comporter au moins 2 caractères.",
+        "de": "Der Benutzername muss mindestens 2 Zeichen lang sein.",
+    },
+    "Password must be at least 4 characters.": {
+        "fr": "Le mot de passe doit comporter au moins 4 caractères.",
+        "de": "Das Passwort muss mindestens 4 Zeichen lang sein.",
+    },
+    "Passwords do not match.": {
+        "fr": "Les mots de passe ne correspondent pas.",
+        "de": "Die Passwörter stimmen nicht überein.",
+    },
+    "Username already taken.": {
+        "fr": "Ce nom d'utilisateur est déjà pris.",
+        "de": "Dieser Benutzername ist bereits vergeben.",
+    },
+    "Household name is required.": {
+        "fr": "Le nom du foyer est requis.",
+        "de": "Der Haushaltsname ist erforderlich.",
+    },
+    "A household with that name already exists.": {
+        "fr": "Un foyer avec ce nom existe déjà.",
+        "de": "Ein Haushalt mit diesem Namen existiert bereits.",
+    },
+    "Please select a household.": {
+        "fr": "Veuillez sélectionner un foyer.",
+        "de": "Bitte wählen Sie einen Haushalt aus.",
+    },
+    "Selected household does not exist.": {
+        "fr": "Le foyer sélectionné n'existe pas.",
+        "de": "Der ausgewählte Haushalt existiert nicht.",
+    },
+    "Account created! Welcome to your household.": {
+        "fr": "Compte créé ! Bienvenue dans votre foyer.",
+        "de": "Konto erstellt! Willkommen in Ihrem Haushalt.",
+    },
+    "Invalid meal type.": {
+        "fr": "Type de repas invalide.",
+        "de": "Ungültige Mahlzeitart.",
+    },
+    "Invalid status.": {
+        "fr": "Statut invalide.",
+        "de": "Ungültiger Status.",
+    },
+    "Invalid date.": {
+        "fr": "Date invalide.",
+        "de": "Ungültiges Datum.",
+    },
+    "Cannot change responses for past dates.": {
+        "fr": "Impossible de modifier les réponses pour les dates passées.",
+        "de": "Antworten für vergangene Daten können nicht geändert werden.",
+    },
+    "Meal period not found.": {
+        "fr": "Période de repas introuvable.",
+        "de": "Mahlzeitenzeitraum nicht gefunden.",
+    },
+    "Invalid date format. Use YYYY-MM-DD.": {
+        "fr": "Format de date invalide. Utilisez AAAA-MM-JJ.",
+        "de": "Ungültiges Datumsformat. Verwenden Sie JJJJ-MM-TT.",
+    },
+    "Incorrect password. Account not deleted.": {
+        "fr": "Mot de passe incorrect. Compte non supprimé.",
+        "de": "Falsches Passwort. Konto nicht gelöscht.",
+    },
+    "Your account and household have been deleted.": {
+        "fr": "Votre compte et votre foyer ont été supprimés.",
+        "de": "Ihr Konto und Ihr Haushalt wurden gelöscht.",
+    },
+    "Your account has been deleted.": {
+        "fr": "Votre compte a été supprimé.",
+        "de": "Ihr Konto wurde gelöscht.",
+    },
+    "Only admins can remove users.": {
+        "fr": "Seuls les administrateurs peuvent retirer des utilisateurs.",
+        "de": "Nur Administratoren können Benutzer entfernen.",
+    },
+    "User not found in your household.": {
+        "fr": "Utilisateur introuvable dans votre foyer.",
+        "de": "Benutzer nicht in Ihrem Haushalt gefunden.",
+    },
+    "Cannot remove the admin. Transfer admin role first or delete the household.": {
+        "fr": "Impossible de retirer l'administrateur. Transférez d'abord le rôle admin ou supprimez le foyer.",
+        "de": "Der Administrator kann nicht entfernt werden. Übertragen Sie zuerst die Admin-Rolle oder löschen Sie den Haushalt.",
+    },
+    "User '{name}' has been removed.": {
+        "fr": "L'utilisateur '{name}' a été retiré.",
+        "de": "Benutzer '{name}' wurde entfernt.",
+    },
+    "Only admins can delete the household.": {
+        "fr": "Seuls les administrateurs peuvent supprimer le foyer.",
+        "de": "Nur Administratoren können den Haushalt löschen.",
+    },
+    "Incorrect password. Household not deleted.": {
+        "fr": "Mot de passe incorrect. Foyer non supprimé.",
+        "de": "Falsches Passwort. Haushalt nicht gelöscht.",
+    },
+    "Household and all members have been deleted.": {
+        "fr": "Le foyer et tous ses membres ont été supprimés.",
+        "de": "Haushalt und alle Mitglieder wurden gelöscht.",
+    },
+}
+
+
+# ── Helpers ───────────────────────────────────────────────────────────────────
+
+def parse_accept_language(header: str | None) -> str:
+    """Parse Accept-Language header and return the best supported language code."""
+    if not header:
+        return FALLBACK
+
+    best = FALLBACK
+    best_quality = 0.0
+
+    for part in header.split(","):
+        chunk = part.strip().split(";")
+        tag = chunk[0].strip().split("-")[0].lower()  # "fr-FR" → "fr"
+        quality = 1.0
+        if len(chunk) > 1 and chunk[1].strip().startswith("q="):
+            try:
+                quality = float(chunk[1].strip()[2:])
+            except ValueError:
+                pass
+
+        if tag in LANGUAGES and quality > best_quality:
+            best_quality = quality
+            best = tag
+
+    return best
+
+
+def get_lang() -> str:
+    """Return current language code (from session, header, or fallback)."""
+    # Session override (user manually selected a language)
+    lang = session.get("lang")
+    if lang and lang in LANGUAGES:
+        return lang
+
+    # Parse Accept-Language header
+    lang = parse_accept_language(request.headers.get("Accept-Language", ""))
+    session["lang"] = lang
+    return lang
+
+
+def t(key: str, **kwargs) -> str:
+    """Translate a key into the current language.
+
+    Usage in templates:  {{ t('Log In') }}
+    With placeholders:   {{ t("User '{name}' has been removed.", name=username) }}
+    """
+    lang = g.get("lang") or session.get("lang") or FALLBACK
+
+    if lang == FALLBACK:
+        result = key
+    else:
+        result = TRANSLATIONS.get(key, {}).get(lang, key)
+
+    if kwargs:
+        result = result.format(**kwargs)
+    return result
+
+
+def init_i18n(app):
+    """Register before_request handler and template globals on a Flask app."""
+
+    @app.before_request
+    def _set_lang():
+        # Allow ?lang= override in query string
+        qs_lang = request.args.get("lang")
+        if qs_lang and qs_lang in LANGUAGES:
+            session["lang"] = qs_lang
+        g.lang = get_lang()
+
+    @app.context_processor
+    def _inject_i18n():
+        return {
+            "t": t,
+            "lang": g.get("lang", FALLBACK),
+            "lang_name": LANGUAGES.get(g.get("lang", FALLBACK), "English"),
+        }

meals.py

@@ -23,6 +23,7 @@ from models import (
     delete_household,
     count_household_users,
 )
+from i18n import t
 
 meals_bp = Blueprint("meals", __name__)
 
@@ -60,7 +61,7 @@ def dashboard():
         try:
             today = datetime.strptime(date_str, "%Y-%m-%d").date()
         except ValueError:
-            flash("Invalid date format. Use YYYY-MM-DD.", "error")
+            flash(t("Invalid date format. Use YYYY-MM-DD."), "error")
 
     if household_id is None:
         session.clear()
@@ -87,27 +88,27 @@ def respond():
     date_str = request.form.get("date", date.today().isoformat())
 
     if meal_type not in ("lunch", "dinner"):
-        flash("Invalid meal type.", "error")
+        flash(t("Invalid meal type."), "error")
         return redirect(url_for("meals.dashboard"))
 
     if status not in ("yes", "no"):
-        flash("Invalid status.", "error")
+        flash(t("Invalid status."), "error")
         return redirect(url_for("meals.dashboard"))
 
     try:
         target_date = datetime.strptime(date_str, "%Y-%m-%d").date()
     except ValueError:
-        flash("Invalid date.", "error")
+        flash(t("Invalid date."), "error")
         return redirect(url_for("meals.dashboard"))
 
     if target_date < date.today():
-        flash("Cannot change responses for past dates.", "error")
+        flash(t("Cannot change responses for past dates."), "error")
         return redirect(url_for("meals.dashboard"))
 
     periods = ensure_meal_periods(target_date)
     period = next((p for p in periods if p["meal_type"] == meal_type), None)
     if period is None:
-        flash("Meal period not found.", "error")
+        flash(t("Meal period not found."), "error")
         return redirect(url_for("meals.dashboard"))
 
     upsert_response(session["user_id"], period["id"], status)
@@ -147,7 +148,7 @@ def delete_account():
     user = get_user_by_id(session["user_id"])
 
     if not check_password_hash(user["password_hash"], password):
-        flash("Incorrect password. Account not deleted.", "error")
+        flash(t("Incorrect password. Account not deleted."), "error")
         return redirect(url_for("meals.dashboard"))
 
     household_id = session["household_id"]
@@ -157,10 +158,10 @@ def delete_account():
     # If admin is the last user, delete the household too
     if is_admin and user_count == 1:
         delete_household(household_id)
-        flash("Your account and household have been deleted.", "success")
+        flash(t("Your account and household have been deleted."), "success")
     else:
         delete_user(session["user_id"])
-        flash("Your account has been deleted.", "success")
+        flash(t("Your account has been deleted."), "success")
 
     # Clear auth keys but keep the session so flash survives the redirect
     for key in ("user_id", "username", "is_admin", "household_id", "household_name"):
@@ -173,20 +174,20 @@ def delete_account():
 def admin_remove_user(user_id):
     """Admin removes a user from the household."""
     if not session["is_admin"]:
-        flash("Only admins can remove users.", "error")
+        flash(t("Only admins can remove users."), "error")
         return redirect(url_for("meals.dashboard"))
 
     user = get_user_by_id(user_id)
     if user is None or user["household_id"] != session["household_id"]:
-        flash("User not found in your household.", "error")
+        flash(t("User not found in your household."), "error")
         return redirect(url_for("meals.dashboard"))
 
     if user["is_admin"]:
-        flash("Cannot remove the admin. Transfer admin role first or delete the household.", "error")
+        flash(t("Cannot remove the admin. Transfer admin role first or delete the household."), "error")
         return redirect(url_for("meals.dashboard"))
 
     delete_user(user_id)
-    flash(f"User '{user['username']}' has been removed.", "success")
+    flash(t("User '{name}' has been removed.", name=user["username"]), "success")
     return redirect(url_for("meals.dashboard"))
 
 
@@ -195,18 +196,18 @@ def admin_remove_user(user_id):
 def admin_delete_household():
     """Admin deletes the entire household."""
     if not session["is_admin"]:
-        flash("Only admins can delete the household.", "error")
+        flash(t("Only admins can delete the household."), "error")
         return redirect(url_for("meals.dashboard"))
 
     password = request.form.get("password", "")
     user = get_user_by_id(session["user_id"])
 
     if not check_password_hash(user["password_hash"], password):
-        flash("Incorrect password. Household not deleted.", "error")
+        flash(t("Incorrect password. Household not deleted."), "error")
         return redirect(url_for("meals.dashboard"))
 
     delete_household(session["household_id"])
-    flash("Household and all members have been deleted.", "success")
+    flash(t("Household and all members have been deleted."), "success")
     for key in ("user_id", "username", "is_admin", "household_id", "household_name"):
         session.pop(key, None)
     return redirect(url_for("auth.login"))

static/style.css

@@ -232,3 +232,25 @@ body {
 .manage-form h4 { margin-bottom: 8px; font-size: 0.9rem; }
 .manage-form .hint { margin-bottom: 8px; }
 .manage-form input[type="password"] { width: 100%; padding: 6px 10px; border: 1px solid var(--border); border-radius: 4px; margin-bottom: 8px; }
+
+/* ── Language footer ── */
+.lang-footer {
+    text-align: center;
+    padding: 16px;
+    margin-top: 32px;
+    border-top: 1px solid var(--border);
+}
+.lang-link {
+    display: inline-block;
+    padding: 4px 10px;
+    margin: 0 4px;
+    font-size: 0.8rem;
+    font-weight: 500;
+    color: var(--muted);
+    text-decoration: none;
+    border-radius: 12px;
+    transition: all 0.15s;
+}
+.lang-link:hover { background: #eee; color: var(--text); }
+.lang-active { background: var(--primary); color: #fff; }
+.lang-active:hover { background: #0d47a1; color: #fff; }

templates/base.html

@@ -1,19 +1,19 @@
 <!doctype html>
-<html lang="en">
+<html lang="{{ lang }}">
 <head>
     <meta charset="utf-8">
     <meta name="viewport" content="width=device-width, initial-scale=1">
-    <title>{% block title %}Meal Tracker{% endblock %}</title>
+    <title>{% block title %}{{ t('Meal Tracker') }}{% endblock %}</title>
     <link rel="stylesheet" href="{{ url_for('static', filename='style.css') }}">
 </head>
 <body>
     <nav class="navbar">
-        <span class="brand">🍽 Meal Tracker</span>
+        <span class="brand">🍽 {{ t('Meal Tracker') }}</span>
         {% if session.user_id %}
         <div class="nav-right">
             <span class="nav-household">{{ session.household_name }}</span>
-            <span class="nav-user">{{ session.username }}{% if session.is_admin %} (admin){% endif %}</span>
+            <span class="nav-user">{{ session.username }}{% if session.is_admin %} ({{ t('admin') }}){% endif %}</span>
-            <a class="btn btn-sm" href="{{ url_for('auth.logout') }}">Logout</a>
+            <a class="btn btn-sm" href="{{ url_for('auth.logout') }}">{{ t('Logout') }}</a>
         </div>
         {% endif %}
     </nav>
@@ -31,5 +31,13 @@
 
         {% block content %}{% endblock %}
     </main>
+
+    <footer class="lang-footer">
+        {% for code, name in {'en': 'English', 'fr': 'Français', 'de': 'Deutsch'}.items() %}
+        <a href="?lang={{ code }}"
+           class="lang-link{% if lang == code %} lang-active{% endif %}"
+           aria-label="{{ name }}">{{ code.upper() }}</a>
+        {% endfor %}
+    </footer>
 </body>
 </html>

templates/dashboard.html

@@ -1,31 +1,31 @@
 {% extends "base.html" %}
-{% block title %}Dashboard — Meal Tracker{% endblock %}
+{% block title %}{{ t('Dashboard — Meal Tracker') }}{% endblock %}
 {% block content %}
 
 <div class="dashboard-header">
     <h2>
-        {% if history_mode %}History — {{ viewing_date.isoformat() }}{% else %}Today's Meals{% endif %}
+        {% if history_mode %}{{ t('History — {date}', date=viewing_date.isoformat()) }}{% else %}{{ t("Today's Meals") }}{% endif %}
     </h2>
     <div class="date-nav">
-        <a class="btn btn-sm" href="?date={{ prev_date.isoformat() }}">◀ Prev</a>
+        <a class="btn btn-sm" href="?date={{ prev_date.isoformat() }}">{{ t('◀ Prev') }}</a>
         <span class="date-display">{{ viewing_date.isoformat() }}</span>
-        <a class="btn btn-sm" href="?date={{ next_date.isoformat() }}">Next ▶</a>
+        <a class="btn btn-sm" href="?date={{ next_date.isoformat() }}">{{ t('Next ▶') }}</a>
         {% if viewing_date != today %}
-        <a class="btn btn-sm" href="{{ url_for('meals.dashboard') }}">Today</a>
+        <a class="btn btn-sm" href="{{ url_for('meals.dashboard') }}">{{ t('Today') }}</a>
         {% endif %}
     </div>
 </div>
 
 {% if not dashboard.users %}
-    <p class="empty-state">No registered users yet. Ask household members to register!</p>
+    <p class="empty-state">{{ t('No registered users yet. Ask household members to register!') }}</p>
 {% else %}
 <div class="table-wrapper">
     <table class="meal-table">
         <thead>
             <tr>
-                <th>User</th>
+                <th>{{ t('User') }}</th>
                 {% for period in dashboard.periods %}
-                <th class="meal-col">{{ period.meal_type|capitalize }}</th>
+                <th class="meal-col">{{ t(period.meal_type|capitalize) }}</th>
                 {% endfor %}
                 {% if is_admin %}
                 <th class="action-col"></th>
@@ -38,8 +38,8 @@
             <tr>
                 <td class="user-cell">
                     {{ user.username }}
-                    {% if user.is_admin %}<span class="admin-tag">admin</span>{% endif %}
+                    {% if user.is_admin %}<span class="admin-tag">{{ t('admin') }}</span>{% endif %}
-                    {% if is_me %}<span class="you-tag">you</span>{% endif %}
+                    {% if is_me %}<span class="you-tag">{{ t('you') }}</span>{% endif %}
                 </td>
                 {% for period in dashboard.periods %}
                 {% set resp = user.responses[period.meal_type] %}
@@ -51,25 +51,26 @@
                         <div class="btn-row">
                             <button name="status" value="yes"
                                     class="chip chip-yes {% if resp.status == 'yes' %}active{% endif %}"
-                            >Home</button>
+                            >{{ t('Home') }}</button>
                             <button name="status" value="no"
                                     class="chip chip-no {% if resp.status == 'no' %}active{% endif %}"
-                            >Out</button>
+                            >{{ t('Out') }}</button>
                         </div>
                     </form>
                     {% if resp.changed_at %}
-                    <div class="changed-badge" title="Changed mind at {{ resp.changed_at }}">↻ {{ resp.changed_at[11:16] }}</div>
+                    <div class="changed-badge" title="{{ t('Changed mind at {time}', time=resp.changed_at) }}">↻ {{ resp.changed_at[11:16] }}</div>
                     {% endif %}
                     {% else %}
-                    <span class="badge badge-{{ resp.status }}">{{ 'Home' if resp.status == 'yes' else ('Out' if resp.status == 'no' else '—') }}</span>
+                    <span class="badge badge-{{ resp.status }}">{{ t('Home') if resp.status == 'yes' else (t('Out') if resp.status == 'no' else t('—')) }}</span>
                     {% endif %}
                 </td>
                 {% endfor %}
                 {% if is_admin and not is_me and not user.is_admin %}
                 <td class="action-cell">
                     <form method="POST" action="{{ url_for('meals.admin_remove_user', user_id=user.id) }}"
-                          onsubmit="return confirm('Remove {{ user.username }} from this household?');">
+                          onsubmit="return confirm(this.dataset.confirmMsg);"
-                        <button class="btn btn-sm btn-danger">Remove</button>
+                          data-confirm-msg="{{ t('Remove {name} from this household?', name=user.username) }}">
+                        <button class="btn btn-sm btn-danger">{{ t('Remove') }}</button>
                     </form>
                 </td>
                 {% elif is_admin %}
@@ -84,22 +85,26 @@
 
 <div class="manage-section">
     <details class="manage-details">
-        <summary>⚙ Account Settings</summary>
+        <summary>{{ t('⚙ Account Settings') }}</summary>
         <div class="manage-forms">
             <form method="POST" action="{{ url_for('meals.delete_account') }}"
-                  onsubmit="return confirm('Delete YOUR account? This cannot be undone.');" class="manage-form">
+                  onsubmit="return confirm(this.dataset.confirmMsg);"
-                <h4>Delete My Account</h4>
+                  data-confirm-msg="{{ t('Delete YOUR account? This cannot be undone.') }}"
-                <input type="password" name="password" placeholder="Enter your password to confirm" required>
+                  class="manage-form">
-                <button class="btn btn-danger">Delete My Account</button>
+                <h4>{{ t('Delete My Account') }}</h4>
+                <input type="password" name="password" placeholder="{{ t('Enter your password to confirm') }}" required>
+                <button class="btn btn-danger">{{ t('Delete My Account') }}</button>
             </form>
 
             {% if is_admin %}
             <form method="POST" action="{{ url_for('meals.admin_delete_household') }}"
-                  onsubmit="return confirm('Delete the ENTIRE household and ALL members? This cannot be undone.');" class="manage-form">
+                  onsubmit="return confirm(this.dataset.confirmMsg);"
-                <h4>Delete Household</h4>
+                  data-confirm-msg="{{ t('Delete the ENTIRE household and ALL members? This cannot be undone.') }}"
-                <p class="hint">This will remove all users and all data in this household.</p>
+                  class="manage-form">
-                <input type="password" name="password" placeholder="Enter your password to confirm" required>
+                <h4>{{ t('Delete Household') }}</h4>
-                <button class="btn btn-danger">Delete Household</button>
+                <p class="hint">{{ t('This will remove all users and all data in this household.') }}</p>
+                <input type="password" name="password" placeholder="{{ t('Enter your password to confirm') }}" required>
+                <button class="btn btn-danger">{{ t('Delete Household') }}</button>
             </form>
             {% endif %}
         </div>

templates/login.html

@@ -1,19 +1,19 @@
 {% extends "base.html" %}
-{% block title %}Login — Meal Tracker{% endblock %}
+{% block title %}{{ t('Login — Meal Tracker') }}{% endblock %}
 {% block content %}
 <div class="form-card">
-    <h2>Log In</h2>
+    <h2>{{ t('Log In') }}</h2>
     <form method="POST">
-        <label for="username">Username</label>
+        <label for="username">{{ t('Username') }}</label>
         <input type="text" id="username" name="username" required autofocus>
 
-        <label for="password">Password</label>
+        <label for="password">{{ t('Password') }}</label>
         <input type="password" id="password" name="password" required>
 
-        <button type="submit" class="btn btn-primary">Log In</button>
+        <button type="submit" class="btn btn-primary">{{ t('Log In') }}</button>
     </form>
     <p class="form-footer">
-        Don't have an account? <a href="{{ url_for('auth.register') }}">Register</a>
+        {{ t("Don't have an account?") }} <a href="{{ url_for('auth.register') }}">{{ t('Register') }}</a>
     </p>
 </div>
 {% endblock %}

templates/register.html

@@ -1,54 +1,54 @@
 {% extends "base.html" %}
-{% block title %}Register — Meal Tracker{% endblock %}
+{% block title %}{{ t('Register — Meal Tracker') }}{% endblock %}
 {% block content %}
 <div class="form-card register-card">
-    <h2>Create Account</h2>
+    <h2>{{ t('Create Account') }}</h2>
     <form method="POST">
-        <label for="username">Username</label>
+        <label for="username">{{ t('Username') }}</label>
         <input type="text" id="username" name="username" required autofocus>
 
-        <label for="password">Password</label>
+        <label for="password">{{ t('Password') }}</label>
         <input type="password" id="password" name="password" required>
 
-        <label for="confirm">Confirm Password</label>
+        <label for="confirm">{{ t('Confirm Password') }}</label>
         <input type="password" id="confirm" name="confirm" required>
 
         <fieldset class="household-section">
-            <legend>Household</legend>
+            <legend>{{ t('Household') }}</legend>
 
             <label class="radio-label">
                 <input type="radio" name="household_action" value="join" id="radio-join" checked>
-                Join an existing household
+                {{ t('Join an existing household') }}
             </label>
             <div id="join-block" class="household-block">
                 <select name="household_id" class="select-input">
-                    <option value="">— Select —</option>
+                    <option value="">{{ t('— Select —') }}</option>
                     {% for h in households %}
                     <option value="{{ h.id }}">{{ h.name }}</option>
                     {% endfor %}
                 </select>
                 {% if not households %}
-                <p class="hint">No households yet. Create one below!</p>
+                <p class="hint">{{ t('No households yet. Create one below!') }}</p>
                 {% endif %}
             </div>
 
             <label class="radio-label">
                 <input type="radio" name="household_action" value="create" id="radio-create"
                        {% if not households %}checked{% endif %}>
-                Create a new household
+                {{ t('Create a new household') }}
             </label>
             <div id="create-block" class="household-block">
                 <input type="text" name="new_household_name"
-                       placeholder="Household name (e.g. The Smiths)"
+                       placeholder="{{ t('Household name (e.g. The Smiths)') }}"
                        class="text-input">
-                <p class="hint">You'll be the admin of this household.</p>
+                <p class="hint">{{ t("You'll be the admin of this household.") }}</p>
             </div>
         </fieldset>
 
-        <button type="submit" class="btn btn-primary">Register</button>
+        <button type="submit" class="btn btn-primary">{{ t('Register') }}</button>
     </form>
     <p class="form-footer">
-        Already have an account? <a href="{{ url_for('auth.login') }}">Log in</a>
+        {{ t('Already have an account?') }} <a href="{{ url_for('auth.login') }}">{{ t('Log in') }}</a>
     </p>
 </div>