fixed another spelling mistake

imprint still unfinished

README.md

@@ -6,7 +6,6 @@ project-root/
 │
 ├── app/
 │   ├── __init__.py          # Flask App Factory
-│   ├── config.py            # Konfiguration (DB, Secrets, etc.)
 │   │
 │   ├── models/              # Datenbankmodelle
 │   │   ├── __init__.py
@@ -22,12 +21,7 @@ project-root/
 │   │   ├── solver_routes.py
 │   │   └── job_routes.py
 │   │
-│   ├── services/            # Businesslogik (Solver etc.)
-│   │   ├── __init__.py
-│   │   ├── solver_service.py
-│   │   └── auth_service.py
-│   │
-│   ├── templates/           # HTML (Jinja Templates)
+│   ├── templates/           # HTML
 │   │   ├── base.html
 │   │   ├── login.html
 │   │   ├── dashboard.html
@@ -42,6 +36,5 @@ project-root/
 │
 ├── run.py                   # Startpunkt der Anwendung
 ├── requirements.txt
-├── .env                     # DB-Zugangsdaten, Secrets
 └── README.md
-```
+```

app/__init__.py

@@ -1,18 +1,30 @@
+"""Application factory and shared Flask extensions.
+
+This file creates the Flask application, configures the database and login
+manager, imports the data models so SQLAlchemy knows about them, and registers
+the route blueprints used by the project.
+"""
+
 import os
 
 from flask import Flask
 from flask_login import LoginManager
 from flask_sqlalchemy import SQLAlchemy
 
+# Shared extension instances are created once here and attached to the app
 db = SQLAlchemy()
 login_manager = LoginManager()
 
 
 def create_app():
+    """Build and configure the Flask application instance."""
     app = Flask(__name__)
 
+    # Build an absolute path to the application directory so the SQLite
+    # database file can be referenced reliably from any working directory.
     BASE_DIR = os.path.abspath(os.path.dirname(__file__))
 
+    # Core Flask and SQLAlchemy configuration.
     app.config["SQLALCHEMY_DATABASE_URI"] = "sqlite:///" + os.path.join(BASE_DIR, "app.db")
     app.config["SECRET_KEY"] = os.getenv("SECRET_KEY", "dev-secret-key")
     app.config["SQLALCHEMY_TRACK_MODIFICATIONS"] = False
@@ -20,22 +32,27 @@ def create_app():
     app.config["REMEMBER_COOKIE_HTTPONLY"] = True
     app.config["SESSION_COOKIE_SAMESITE"] = "Lax"
 
+    # Connect the shared extension objects to this specific app instance.
     db.init_app(app)
     login_manager.init_app(app)
     login_manager.login_view = "login.login"
     login_manager.login_message_category = "info"
 
+    # Import the models before create_all() so SQLAlchemy has the table
     from .models.user import User
     from .models.gamestate import GameState
     from .models.login_attempt import LoginAttempt
 
+    # Create any database tables that do not exist yet.
     with app.app_context():
         db.create_all()
 
     @login_manager.user_loader
     def load_user(user_id):
+        """Reload the logged-in user from the session-stored user id."""
         return db.session.get(User, int(user_id))
 
+    # Import and register the blueprints that contain the route handlers.
     from .routes.login_routes import login_bp
     from .routes.main_routes import main_bp
 

app/routes/login_routes.py

@@ -1,3 +1,11 @@
+"""Authentication routes and login-related helper functions.
+
+This module handles user registration, login, logout, password changes,
+login-attempt throttling, and authenticator-app based two-factor
+authentication. It also contains the utility functions that keep these flows
+consistent across the different route handlers.
+"""
+
 import base64
 import binascii
 import hashlib
@@ -16,11 +24,13 @@ from .. import db
 from ..models.login_attempt import LoginAttempt
 from ..models.user import User
 
+# Blueprint that groups all authentication and account-security routes.
 login_bp = Blueprint("login", __name__)
 
+# constants
 MIN_PASSWORD_LENGTH = 8
 MAX_PASSWORD_LENGTH = 128
-MAX_LOGIN_FAILURES = 5
+MAX_LOGIN_FAILURES = 8
 LOGIN_LOCK_MINUTES = 15
 TWO_FACTOR_CODE_DIGITS = 6
 TWO_FACTOR_TIME_STEP_SECONDS = 30
@@ -32,10 +42,12 @@ DUMMY_PASSWORD_HASH = generate_password_hash("dummy-password-for-timing-protecti
 
 
 def utcnow():
+    """Return the current UTC time as datetime."""
     return datetime.utcnow()
 
 
 def get_utc_timestamp(moment=None):
+    """Convert a datetime into a Unix timestamp in UTC seconds."""
     if moment is None:
         return int(datetime.now(timezone.utc).timestamp())
 
@@ -46,16 +58,19 @@ def get_utc_timestamp(moment=None):
 
 
 def normalize_username(username):
+    """Trim surrounding whitespace from the username field."""
     return (username or "").strip()
 
 
 def validate_username(username):
+    """Return an error message if the username violates the allowed pattern."""
     if not USERNAME_PATTERN.fullmatch(username):
         return "Username must be 3-20 characters and only use letters, numbers, dots, dashes, or underscores."
     return None
 
 
 def validate_password(password):
+    """Return an error message if the password length is outside the allowed range."""
     if len(password) < MIN_PASSWORD_LENGTH:
         return f"Password must be at least {MIN_PASSWORD_LENGTH} characters long."
 
@@ -66,6 +81,7 @@ def validate_password(password):
 
 
 def get_request_ip():
+    """Determine the client IP address, preferring a reverse-proxy header when present."""
     forwarded_for = request.headers.get("X-Forwarded-For", "")
 
     if forwarded_for:
@@ -75,6 +91,11 @@ def get_request_ip():
 
 
 def login_attempt_buckets(username):
+    """Return the lockout buckets tracked for this login attempt.
+
+    The app tracks failures both per username+IP and per IP-only bucket to
+    slow down brute-force attempts against many usernames from the same client.
+    """
     normalized_username = normalize_username(username).lower() or "__empty__"
     ip_address = get_request_ip()
     return [
@@ -84,6 +105,7 @@ def login_attempt_buckets(username):
 
 
 def get_or_create_attempt(ip_address, bucket_key):
+    """Fetch an existing login-attempt record or create a new one."""
     attempt = LoginAttempt.query.filter_by(ip_address=ip_address, username=bucket_key).first()
 
     if attempt is None:
@@ -94,12 +116,14 @@ def get_or_create_attempt(ip_address, bucket_key):
 
 
 def clear_expired_lock(attempt, now):
+    """Reset the failure counter when a temporary lockout has expired."""
     if attempt.locked_until and attempt.locked_until <= now:
         attempt.failed_attempts = 0
         attempt.locked_until = None
 
 
 def get_active_lock(username):
+    """Return the latest active lockout time for this username/IP combination."""
     now = utcnow()
     active_until = None
 
@@ -119,6 +143,7 @@ def get_active_lock(username):
 
 
 def record_failed_login(username):
+    """Increase the failure counter and start a temporary lock when needed."""
     now = utcnow()
     locked_until = None
 
@@ -137,6 +162,7 @@ def record_failed_login(username):
 
 
 def clear_login_attempts(username):
+    """Remove tracked failed attempts after a successful login."""
     for ip_address, bucket_key in login_attempt_buckets(username):
         attempt = LoginAttempt.query.filter_by(ip_address=ip_address, username=bucket_key).first()
 
@@ -147,6 +173,7 @@ def clear_login_attempts(username):
 
 
 def lookup_user_by_username(username):
+    """Look up a user case-insensitively so login is not case-sensitive."""
     if not username:
         return None
 
@@ -154,29 +181,35 @@ def lookup_user_by_username(username):
 
 
 def minutes_until(target_time):
+    """Return the remaining lockout time in rounded-up whole minutes."""
     seconds = max(1, int((target_time - utcnow()).total_seconds()))
     return max(1, (seconds + 59) // 60)
 
 
 def normalize_two_factor_secret(secret):
+    """Normalize a Base32 secret by removing spaces and uppercasing it."""
     return (secret or "").strip().replace(" ", "").upper()
 
 
 def generate_two_factor_secret():
+    """Generate a new random Base32 secret for authenticator apps."""
     return base64.b32encode(secrets.token_bytes(20)).decode("ascii").rstrip("=")
 
 
 def format_two_factor_secret(secret):
+    """Insert spaces into the secret to make manual entry easier."""
     normalized = normalize_two_factor_secret(secret)
     return " ".join(normalized[index:index + 4] for index in range(0, len(normalized), 4))
 
 
 def clear_pending_two_factor(user=None):
+    """Remove the session values used during the login 2FA verification step."""
     session.pop("pending_2fa_user_id", None)
     session.pop("pending_2fa_attempts", None)
 
 
 def get_pending_two_factor_setup_secret(user):
+    """Return the temporary secret generated during 2FA setup for this user."""
     if session.get("pending_2fa_setup_user_id") != user.id:
         return None
 
@@ -185,11 +218,13 @@ def get_pending_two_factor_setup_secret(user):
 
 
 def clear_pending_two_factor_setup():
+    """Remove the session values used during authenticator setup."""
     session.pop("pending_2fa_setup_user_id", None)
     session.pop("pending_2fa_setup_secret", None)
 
 
 def build_totp_uri(user, secret):
+    """Build the otpauth URI consumed by authenticator applications."""
     normalized_secret = normalize_two_factor_secret(secret)
     label = quote(f"{TWO_FACTOR_ISSUER}:{user.username}")
     issuer = quote(TWO_FACTOR_ISSUER)
@@ -201,12 +236,14 @@ def build_totp_uri(user, secret):
 
 
 def decode_two_factor_secret(secret):
+    """Decode the Base32 secret into raw bytes for HMAC processing."""
     normalized_secret = normalize_two_factor_secret(secret)
     padded_secret = normalized_secret + ("=" * (-len(normalized_secret) % 8))
     return base64.b32decode(padded_secret, casefold=True)
 
 
 def generate_totp_code(secret, for_time=None):
+    """Generate a time-based one-time password from the shared secret."""
     timestamp = get_utc_timestamp(for_time)
     counter = timestamp // TWO_FACTOR_TIME_STEP_SECONDS
     key = decode_two_factor_secret(secret)
@@ -219,6 +256,7 @@ def generate_totp_code(secret, for_time=None):
 
 
 def verify_totp_code(secret, code, at_time=None):
+    """Validate a 2FA code, allowing a small time window for clock drift."""
     normalized_code = (code or "").strip()
 
     if not normalized_code.isdigit() or len(normalized_code) != TWO_FACTOR_CODE_DIGITS:
@@ -239,6 +277,7 @@ def verify_totp_code(secret, code, at_time=None):
 
 
 def get_pending_two_factor_user():
+    """Load the user who is currently in the middle of the login 2FA step."""
     user_id = session.get("pending_2fa_user_id")
 
     if not user_id:
@@ -248,6 +287,7 @@ def get_pending_two_factor_user():
 
 
 def render_login_settings(error=None):
+    """Render the login settings page with optional 2FA setup data."""
     pending_secret = get_pending_two_factor_setup_secret(current_user)
     formatted_secret = format_two_factor_secret(pending_secret) if pending_secret else None
     provisioning_uri = build_totp_uri(current_user, pending_secret) if pending_secret else None
@@ -262,6 +302,7 @@ def render_login_settings(error=None):
 
 @login_bp.route("/register", methods=["GET", "POST"])
 def register():
+    """Create a new user account after validating the submitted credentials."""
     if current_user.is_authenticated:
         return redirect(url_for("main.dashboard"))
 
@@ -293,6 +334,7 @@ def register():
 
 @login_bp.route("/login", methods=["GET", "POST"])
 def login():
+    """Authenticate a user and start the 2FA step when required."""
     if current_user.is_authenticated:
         return redirect(url_for("main.dashboard"))
 
@@ -303,6 +345,7 @@ def login():
         if not username or not password:
             return render_template("login.html", error="Username and password are required.", username=username)
 
+        # Stop early if this user or IP bucket is currently locked.
         locked_until = get_active_lock(username)
 
         if locked_until and locked_until > utcnow():
@@ -313,6 +356,8 @@ def login():
             )
 
         user = lookup_user_by_username(username)
+        # Use a dummy hash when the user does not exist so the timing stays
+        # similar and does not reveal valid usernames.
         password_hash = user.password if user else DUMMY_PASSWORD_HASH
         password_matches = check_password_hash(password_hash, password)
 
@@ -330,6 +375,7 @@ def login():
         clear_login_attempts(username)
 
         if user.two_factor_enabled:
+            # Delay the full login until the authenticator code has been verified.
             if not user.two_factor_secret:
                 return render_template(
                     "login.html",
@@ -353,6 +399,7 @@ def login():
 
 @login_bp.route("/login/verify", methods=["GET", "POST"])
 def verify_two_factor():
+    """Complete login by verifying the authenticator-app code."""
     if current_user.is_authenticated:
         return redirect(url_for("main.dashboard"))
 
@@ -373,6 +420,7 @@ def verify_two_factor():
 
         attempts = int(session.get("pending_2fa_attempts", 0))
 
+        # Limit repeated guesses during the second factor step as well.
         if attempts >= MAX_TWO_FACTOR_ATTEMPTS:
             clear_pending_two_factor(user)
             db.session.commit()
@@ -413,6 +461,7 @@ def verify_two_factor():
 @login_bp.route("/login/settings", methods=["GET", "POST"])
 @login_required
 def login_settings():
+    """Handle password changes and authenticator-based 2FA settings."""
     if request.method == "POST":
         action = request.form.get("action")
 
@@ -420,6 +469,8 @@ def login_settings():
             if current_user.two_factor_enabled:
                 return render_login_settings(error="Authenticator app 2FA is already enabled.")
 
+            # Store the generated secret in the session until the user confirms
+            # it with a valid authenticator code.
             secret = generate_two_factor_secret()
             session["pending_2fa_setup_user_id"] = current_user.id
             session["pending_2fa_setup_secret"] = secret
@@ -486,6 +537,7 @@ def login_settings():
 @login_bp.route("/logout", methods=["POST"])
 @login_required
 def logout():
+    """Log the user out and clear any unfinished authentication state."""
     clear_pending_two_factor()
     clear_pending_two_factor_setup()
     logout_user()

app/routes/main_routes.py

@@ -1,3 +1,10 @@
+"""Main application routes for pages, puzzle solving, and save points.
+
+This module contains the public pages, the dashboard, the board validation
+logic for queens and rooks, solver endpoints, and the CRUD-style endpoints
+used to store and restore saved games for a logged-in user.
+"""
+
 import json
 import random
 from datetime import datetime
@@ -12,10 +19,58 @@ DEFAULT_BOARD_SIZE = 8
 MIN_BOARD_SIZE = 4
 MAX_BOARD_SIZE = 13
 
+# Blueprint that groups the main site and game-related routes.
 main_bp = Blueprint("main", __name__)
 
 
+def create_empty_board(board_size):
+    """Create a square board matrix with no placed pieces."""
+    return [[0 for _ in range(board_size)] for _ in range(board_size)]
+
+
+def build_board_from_positions(piece_positions, board_size):
+    """Convert the legacy one-piece-per-row format into a board matrix."""
+    board = create_empty_board(board_size)
+
+    for row, col in enumerate(piece_positions):
+        if isinstance(col, int) and 0 <= col < board_size:
+            board[row][col] = 1
+
+    return board
+
+
+def normalize_board(candidate_board, board_size):
+    """Normalize stored boards so legacy and matrix formats can both be used."""
+    if not isinstance(candidate_board, list) or len(candidate_board) != board_size:
+        return create_empty_board(board_size)
+
+    if all(isinstance(row, list) and len(row) == board_size for row in candidate_board):
+        normalized_board = create_empty_board(board_size)
+
+        for row_index, row in enumerate(candidate_board):
+            for col_index, value in enumerate(row):
+                normalized_board[row_index][col_index] = 1 if value else 0
+
+        return normalized_board
+
+    return build_board_from_positions(candidate_board, board_size)
+
+
+def iter_piece_positions(board):
+    """Yield every occupied square from the normalized board matrix."""
+    for row_index, row in enumerate(board):
+        for col_index, value in enumerate(row):
+            if value:
+                yield row_index, col_index
+
+
+def count_placed_pieces(board):
+    """Count how many pieces are currently placed on the board."""
+    return sum(1 for _ in iter_piece_positions(board))
+
+
 def parse_board_size(raw_size, default=DEFAULT_BOARD_SIZE):
+    """Convert a user-supplied board size into a safe integer range."""
     try:
         board_size = int(raw_size)
     except (TypeError, ValueError):
@@ -25,10 +80,12 @@ def parse_board_size(raw_size, default=DEFAULT_BOARD_SIZE):
 
 
 def parse_favorite_flag(raw_value):
+    """Interpret common truthy values from query parameters or JSON payloads."""
     return str(raw_value).lower() in {"1", "true", "yes", "on"}
 
 
 def parse_non_negative_int(raw_value, default=0):
+    """Parse an integer and clamp negative values to zero."""
     try:
         value = int(raw_value)
     except (TypeError, ValueError):
@@ -38,14 +95,17 @@ def parse_non_negative_int(raw_value, default=0):
 
 
 def get_position_label(row, col, board_size):
+    """Return a chess-style board label such as A8 or C5."""
     return f"{chr(65 + col)}{board_size - row}"
 
 
 def solve_queens(board_size):
+    """Return every valid N-Queens solution for the requested board size."""
     queen_positions = [-1] * board_size
     queen_solutions = []
 
     def is_queen_position_safe(row, col):
+        """Check whether the new queen conflicts with any earlier queen."""
         for previous_row in range(row):
             previous_col = queen_positions[previous_row]
 
@@ -58,6 +118,7 @@ def solve_queens(board_size):
         return True
 
     def place_queen(row):
+        """Backtracking search that fills the board row by row."""
         if row == board_size:
             queen_solutions.append(queen_positions[:])
             return
@@ -73,16 +134,19 @@ def solve_queens(board_size):
 
 
 def solve_rooks(board_size):
+    """Return one valid rook arrangement with exactly one rook per row/column."""
     rook_positions = list(range(board_size))
     random.shuffle(rook_positions)
     return rook_positions
 
 
 def build_queens_trace(board_size):
+    """Build a step-by-step trace that explains the queens backtracking search."""
     queen_positions = [-1] * board_size
     steps = []
 
     def is_queen_position_safe(row, col):
+        """Reuse the same safety rules used by the queens solver."""
         for previous_row in range(row):
             previous_col = queen_positions[previous_row]
 
@@ -95,13 +159,14 @@ def build_queens_trace(board_size):
         return True
 
     def place_queen(row):
+        """Record every placement and backtracking step until a solution is found."""
         if row == board_size:
             steps.append({
                 "type": "solution",
                 "row": None,
                 "col": None,
-                "board": queen_positions[:],
-                "message": f"Loesung gefunden. Alle {board_size} Damen stehen ohne Konflikte."
+                "board": build_board_from_positions(queen_positions, board_size),
+                "message": f"Lösung gefunden. Alle {board_size} Damen stehen ohne Konflikte."
             })
             return True
 
@@ -111,11 +176,13 @@ def build_queens_trace(board_size):
 
             queen_positions[row] = col
             position = get_position_label(row, col, board_size)
+            # Store a snapshot of the current board so the frontend can replay
+            # the solving process visually.
             steps.append({
                 "type": "place",
                 "row": row,
                 "col": col,
-                "board": queen_positions[:],
+                "board": build_board_from_positions(queen_positions, board_size),
                 "message": f"Dame auf {position} gesetzt."
             })
 
@@ -127,7 +194,7 @@ def build_queens_trace(board_size):
                 "type": "remove",
                 "row": row,
                 "col": col,
-                "board": queen_positions[:],
+                "board": build_board_from_positions(queen_positions, board_size),
                 "message": f"Backtracking: Dame von {position} entfernt."
             })
 
@@ -138,25 +205,28 @@ def build_queens_trace(board_size):
     return {
         "mode": "queens",
         "board_size": board_size,
-        "initial_board": [-1] * board_size,
+        "initial_board": create_empty_board(board_size),
         "steps": steps,
         "solved": solved
     }
 
 
 def build_rooks_trace(board_size):
+    """Build a simple placement trace for the rook mode."""
     rook_positions = solve_rooks(board_size)
-    board = [-1] * board_size
+    board = create_empty_board(board_size)
     steps = []
 
     for row, col in enumerate(rook_positions):
-        board[row] = col
+        board[row][col] = 1
         position = get_position_label(row, col, board_size)
+        # As with the queens trace, each step includes a full board snapshot for
+        # straightforward frontend rendering.
         steps.append({
             "type": "place",
             "row": row,
             "col": col,
-            "board": board[:],
+            "board": [board_row[:] for board_row in board],
             "message": f"Turm auf {position} gesetzt."
         })
 
@@ -164,21 +234,22 @@ def build_rooks_trace(board_size):
         "type": "solution",
         "row": None,
         "col": None,
-        "board": board[:],
+        "board": [board_row[:] for board_row in board],
         "message": f"Loesung gefunden. Alle {board_size} Tuerme stehen ohne Konflikte."
     })
 
     return {
         "mode": "rooks",
         "board_size": board_size,
-        "initial_board": [-1] * board_size,
+        "initial_board": create_empty_board(board_size),
         "steps": steps,
         "solved": True
     }
 
 
 def serialize_game_state(game_state):
-    board = json.loads(game_state.board)
+    """Convert a database model into JSON-friendly data for the frontend."""
+    board = normalize_board(json.loads(game_state.board), game_state.board_size)
 
     return {
         "id": game_state.id,
@@ -188,7 +259,7 @@ def serialize_game_state(game_state):
         "save_name": game_state.save_name,
         "save_note": game_state.save_note,
         "is_favorite": game_state.is_favorite,
-        "pieces_placed": sum(1 for column in board if column != -1),
+        "pieces_placed": count_placed_pieces(board),
         "step_count": game_state.step_count,
         "elapsed_seconds": game_state.elapsed_seconds,
         "is_solved": game_state.is_solved,
@@ -198,6 +269,7 @@ def serialize_game_state(game_state):
 
 
 def build_save_point_query():
+    """Create a filtered and sorted query for the current user's save points."""
     query = GameState.query.filter_by(user_id=current_user.id)
 
     selected_mode = request.args.get("mode")
@@ -205,6 +277,7 @@ def build_save_point_query():
     favorites_only = request.args.get("favorites_only")
     sort_by = request.args.get("sort", "newest")
 
+    # Apply optional filters only when the request contains a supported value.
     if selected_mode in {"queens", "rooks"}:
         query = query.filter_by(mode=selected_mode)
 
@@ -226,6 +299,7 @@ def build_save_point_query():
 
 @main_bp.route("/")
 def home():
+    """Render the public landing page and choose a matching default language."""
     initial_language = request.accept_languages.best_match(["de", "en"]) or "de"
     return render_template("index.html", initial_language=initial_language)
 
@@ -233,27 +307,44 @@ def home():
 @main_bp.route("/dashboard")
 @login_required
 def dashboard():
+    """Render the logged-in dashboard."""
     return render_template("dashboard.html", user=current_user)
 
 
+@main_bp.route("/privacy_policy")
+def privacy_policy():
+    """Render the privacy policy page."""
+    return render_template("privacy.html")
+
+
+@main_bp.route("/imprint")
+def imprint():
+    """Render the imprint/legal notice page."""
+    return render_template("impressum.html")
+
+
 @main_bp.route("/check", methods=["POST"])
 def check():
+    """Validate whether a piece can be placed on the requested square."""
     data = request.json
     board = data["board"]
     row = data["row"]
     col = data["col"]
     piece_mode = data.get("mode", "queens")
+    normalized_board = normalize_board(board, len(board))
 
-    for current_row, current_col in enumerate(board):
-        if current_col == -1 or current_row == row:
+    for current_row, current_col in iter_piece_positions(normalized_board):
+        if current_row == row and current_col == col:
             continue
 
+        same_row = current_row == row
         same_column = current_col == col
         same_diagonal = abs(current_col - col) == abs(current_row - row)
 
-        if same_column:
+        if same_row or same_column:
             return jsonify({"valid": False})
 
+        # Diagonal conflicts only matter for queens, not for rooks.
         if piece_mode == "queens" and same_diagonal:
             return jsonify({"valid": False})
 
@@ -262,24 +353,28 @@ def check():
 
 @main_bp.route("/solve")
 def solve_queens_route():
+    """Return all queens solutions for the requested board size."""
     board_size = parse_board_size(request.args.get("size"))
     return jsonify(solve_queens(board_size))
 
 
 @main_bp.route("/solve_trace")
 def solve_queens_trace_route():
+    """Return a step-by-step queens solving trace."""
     board_size = parse_board_size(request.args.get("size"))
     return jsonify(build_queens_trace(board_size))
 
 
 @main_bp.route("/solve_rooks")
 def solve_rooks_route():
+    """Return one rook solution for the requested board size."""
     board_size = parse_board_size(request.args.get("size"))
     return jsonify(solve_rooks(board_size))
 
 
 @main_bp.route("/solve_rooks_trace")
 def solve_rooks_trace_route():
+    """Return a step-by-step rook placement trace."""
     board_size = parse_board_size(request.args.get("size"))
     return jsonify(build_rooks_trace(board_size))
 
@@ -287,6 +382,7 @@ def solve_rooks_trace_route():
 @main_bp.route("/save", methods=["POST"])
 @login_required
 def save_game():
+    """Store the current board state as a new save point for the user."""
     data = request.json
 
     board = data["board"]
@@ -300,6 +396,7 @@ def save_game():
     is_solved = bool(data.get("isSolved"))
     timestamp = datetime.utcnow()
 
+    # Save the board as JSON text so it can be restored exactly as the user left it.
     game_state = GameState(
         user_id=current_user.id,
         board=json.dumps(board),
@@ -327,6 +424,7 @@ def save_game():
 @main_bp.route("/save_points")
 @login_required
 def list_save_points():
+    """Return all save points for the current user after filtering and sorting."""
     save_points = build_save_point_query().all()
     return jsonify([serialize_game_state(game_state) for game_state in save_points])
 
@@ -334,6 +432,7 @@ def list_save_points():
 @main_bp.route("/save_points/<int:game_id>/favorite", methods=["POST"])
 @login_required
 def toggle_save_point_favorite(game_id):
+    """Toggle the favorite flag for one saved game."""
     game_state = GameState.query.filter_by(id=game_id, user_id=current_user.id).first()
 
     if not game_state:
@@ -348,6 +447,7 @@ def toggle_save_point_favorite(game_id):
 @main_bp.route("/save_points/<int:game_id>", methods=["DELETE"])
 @login_required
 def delete_save_point(game_id):
+    """Delete one save point owned by the current user."""
     game_state = GameState.query.filter_by(id=game_id, user_id=current_user.id).first()
 
     if not game_state:
@@ -362,14 +462,16 @@ def delete_save_point(game_id):
 @main_bp.route("/load")
 @login_required
 def load_game():
+    """Load the newest save point for the current user."""
     latest_game = (
         GameState.query.filter_by(user_id=current_user.id)
         .order_by(GameState.created_at.desc(), GameState.id.desc())
         .first()
     )
 
+    # If the user has never saved a game, return a clean default board.
     if not latest_game:
-        return jsonify({"board": [-1] * DEFAULT_BOARD_SIZE, "mode": "queens"})
+        return jsonify({"board": create_empty_board(DEFAULT_BOARD_SIZE), "mode": "queens"})
 
     return jsonify(serialize_game_state(latest_game))
 
@@ -377,6 +479,7 @@ def load_game():
 @main_bp.route("/load/<int:game_id>")
 @login_required
 def load_specific_game(game_id):
+    """Load a specific save point owned by the current user."""
     game_state = GameState.query.filter_by(id=game_id, user_id=current_user.id).first()
 
     if not game_state:

app/static/css/dashboard.css

@@ -117,6 +117,7 @@ textarea {
 
 .lang-switch {
     min-width: 68px;
+    border-color: rgba(231, 191, 119, 0.45);
 }
 
 .nav-link:hover,
@@ -482,9 +483,17 @@ textarea {
     line-height: 1.55;
 }
 
-.board {
+.board-stage {
+    display: grid;
+    gap: 14px;
+    justify-items: center;
+    margin-top: 10px;
+}
+
+.board-shell {
     overflow-x: auto;
     padding-bottom: 8px;
+    width: 100%;
 }
 
 .board-grid {
@@ -543,30 +552,30 @@ textarea {
     background: #d65555 !important;
 }
 
-.solver-panel {
-    margin-top: 18px;
-    padding: 18px;
-    border-radius: 12px;
-    border: 1px solid rgba(31, 49, 64, 0.1);
-    background: rgba(255, 250, 242, 0.74);
-    text-align: left;
-}
-
-.solver-panel-header {
-    display: flex;
-    justify-content: space-between;
-    align-items: flex-start;
-    gap: 16px;
-}
-
-.solver-panel h3 {
-    margin-bottom: 8px;
-}
-
 .solver-message {
     margin: 0;
 }
 
+.board-navigator {
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    flex-wrap: wrap;
+    gap: 10px;
+    width: min(100%, 620px);
+}
+
+.board-nav-button {
+    min-width: 150px;
+}
+
+.solver-message-inline {
+    margin: 0 auto;
+    max-width: 760px;
+    text-align: center;
+    font-size: 15px;
+}
+
 .solver-step-info {
     margin: 0;
     padding: 8px 12px;
@@ -578,63 +587,31 @@ textarea {
     white-space: nowrap;
 }
 
-.solver-groups {
-    display: grid;
-    grid-template-columns: minmax(0, 1.35fr) minmax(260px, 0.65fr);
-    gap: 16px;
-    margin-top: 18px;
-}
-
-.solver-group {
-    padding: 18px;
-    border: 1px solid rgba(31, 49, 64, 0.1);
-    background: rgba(255, 255, 255, 0.58);
-}
-
-.solver-group h4 {
-    margin: 0 0 8px;
-    color: #182029;
-    font-size: 1.15rem;
-}
-
-.solver-group-text {
-    margin: 0;
-    font-size: 15px;
-}
-
-.solver-controls {
-    display: grid;
-    grid-template-columns: repeat(3, minmax(0, 1fr));
-    gap: 10px;
-    margin-top: 16px;
-}
-
-.instant-solver-actions {
-    margin-top: 16px;
-}
-
-.instant-solver-actions .btn {
-    width: 100%;
-}
-
 .solver-speed {
     display: grid;
-    grid-template-columns: auto 1fr auto;
-    align-items: center;
+    grid-template-columns: minmax(0, 1fr) auto;
+    grid-template-areas:
+        "label label"
+        "input value";
+    align-items: end;
     gap: 12px;
     margin-top: 16px;
 }
 
 .solver-speed input[type="range"] {
+    grid-area: input;
     width: 100%;
+    min-width: 0;
 }
 
 .solver-speed-label {
+    grid-area: label;
     font-weight: 700;
     color: var(--navy);
 }
 
 .solver-speed-value {
+    grid-area: value;
     min-width: 62px;
     text-align: right;
     color: var(--muted);
@@ -649,19 +626,6 @@ textarea {
     gap: 10px;
 }
 
-.controls-save-row {
-    display: grid;
-    grid-template-columns: repeat(2, minmax(0, 1fr));
-    gap: 10px;
-    width: min(420px, 100%);
-}
-
-.settings-sidebar-actions {
-    margin-top: 18px;
-    display: grid;
-    gap: 10px;
-}
-
 .section-header,
 .history-header,
 .sidebar-header,
@@ -785,6 +749,34 @@ textarea {
     width: min(400px, 94vw);
 }
 
+.settings-section {
+    margin-top: 22px;
+    padding-top: 22px;
+    border-top: 1px solid rgba(31, 49, 64, 0.1);
+}
+
+.settings-section:first-of-type {
+    margin-top: 0;
+    padding-top: 0;
+    border-top: 0;
+}
+
+.settings-section h4 {
+    margin: 0;
+    color: #182029;
+    font-size: 1.15rem;
+}
+
+.settings-section .section-kicker {
+    margin-bottom: 10px;
+}
+
+.settings-action-grid {
+    display: grid;
+    gap: 10px;
+    margin-top: 16px;
+}
+
 .sidebar-label {
     display: block;
     margin-top: 18px;
@@ -979,14 +971,6 @@ textarea {
 }
 
 @media (max-width: 980px) {
-    .solver-groups {
-        grid-template-columns: 1fr;
-    }
-
-    .solver-controls {
-        grid-template-columns: 1fr;
-    }
-
     .game-card-header,
     .history-header,
     .section-header {
@@ -1039,7 +1023,7 @@ textarea {
         padding-right: 8px;
     }
 
-    .board {
+    .board-shell {
         margin-left: -4px;
         margin-right: -4px;
         padding-bottom: 4px;
@@ -1060,6 +1044,10 @@ textarea {
         grid-template-columns: 1fr;
     }
 
+    .board-navigator {
+        width: 100%;
+    }
+
     .mode-switch .btn {
         min-width: min(100%, 280px);
     }
@@ -1069,14 +1057,11 @@ textarea {
     }
 
     .controls>.btn,
+    .board-nav-button,
     .save-point-actions .btn {
         width: 100%;
     }
 
-    .controls-save-row {
-        width: 100%;
-    }
-
     .sidebar {
         width: min(100%, calc(100vw - 24px));
     }

app/static/css/footer.css

@@ -0,0 +1,111 @@
+:root {
+    --footer-surface: rgba(18, 33, 45, 0.94);
+    --footer-line: rgba(231, 191, 119, 0.28);
+    --footer-text: #f7f1e6;
+    --footer-muted: rgba(247, 241, 230, 0.72);
+    --footer-link-bg: rgba(255, 255, 255, 0.06);
+}
+
+body {
+    display: flex;
+    flex-direction: column;
+}
+
+body > main,
+body > .container {
+    flex: 1 0 auto;
+}
+
+body > main.auth-shell {
+    min-height: 0;
+}
+
+.page-footer {
+    margin-top: 32px;
+    border-top: 1px solid var(--footer-line);
+    background:
+        linear-gradient(180deg, rgba(17, 29, 39, 0.98), rgba(31, 49, 64, 0.96));
+    color: var(--footer-text);
+    box-shadow: 0 -18px 40px rgba(31, 49, 64, 0.08);
+}
+
+.page-footer-inner {
+    width: min(1200px, calc(100vw - 32px));
+    margin: 0 auto;
+    padding: 26px 0 30px;
+    display: flex;
+    align-items: center;
+    justify-content: space-between;
+    gap: 20px;
+}
+
+.page-footer-copy {
+    display: grid;
+    gap: 10px;
+}
+
+.page-footer-brand {
+    display: inline-flex;
+    align-items: center;
+    gap: 12px;
+    font-weight: 700;
+    letter-spacing: 0.03em;
+}
+
+.page-footer-mark {
+    width: 38px;
+    height: 38px;
+    display: grid;
+    place-items: center;
+    border-radius: 8px;
+    background: linear-gradient(135deg, #c68b2c, #e7bf77);
+    color: #2c2215;
+    font-size: 21px;
+}
+
+.page-footer-text {
+    margin: 0;
+    font-family: "Trebuchet MS", "Segoe UI", sans-serif;
+    color: var(--footer-muted);
+    line-height: 1.6;
+}
+
+.page-footer-links {
+    display: flex;
+    align-items: center;
+    flex-wrap: wrap;
+    justify-content: flex-end;
+    gap: 12px;
+}
+
+.page-footer-links a {
+    display: inline-flex;
+    align-items: center;
+    justify-content: center;
+    min-height: 44px;
+    padding: 10px 16px;
+    border: 1px solid rgba(231, 191, 119, 0.24);
+    background: var(--footer-link-bg);
+    color: var(--footer-text);
+    font-family: "Trebuchet MS", "Segoe UI", sans-serif;
+    font-weight: 700;
+    transition: transform 0.2s ease, border-color 0.2s ease, background 0.2s ease;
+}
+
+.page-footer-links a:hover {
+    transform: translateY(-2px);
+    border-color: rgba(231, 191, 119, 0.45);
+    background: rgba(255, 255, 255, 0.1);
+}
+
+@media (max-width: 760px) {
+    .page-footer-inner {
+        padding: 22px 0 26px;
+        flex-direction: column;
+        align-items: flex-start;
+    }
+
+    .page-footer-links {
+        justify-content: flex-start;
+    }
+}

app/static/css/legal.css

@@ -0,0 +1,220 @@
+:root {
+    --bg: #f4efe7;
+    --surface: rgba(255, 250, 242, 0.9);
+    --surface-strong: #fffaf2;
+    --text: #1e1f1d;
+    --muted: #5f615c;
+    --navy: #1f3140;
+    --navy-soft: #324d63;
+    --gold: #c68b2c;
+    --gold-soft: #e7bf77;
+    --line: rgba(31, 49, 64, 0.12);
+    --shadow: 0 24px 60px rgba(37, 42, 48, 0.14);
+}
+
+*,
+*::before,
+*::after {
+    box-sizing: border-box;
+}
+
+body {
+    margin: 0;
+    min-height: 100vh;
+    color: var(--text);
+    font-family: Georgia, "Times New Roman", serif;
+    background:
+        radial-gradient(circle at top left, rgba(255, 255, 255, 0.9), transparent 24%),
+        radial-gradient(circle at 82% 18%, rgba(198, 139, 44, 0.2), transparent 20%),
+        linear-gradient(180deg, #f7f0e5 0%, #efe5d5 52%, #f4efe7 100%);
+}
+
+a {
+    color: inherit;
+    text-decoration: none;
+}
+
+.legal-header {
+    position: sticky;
+    top: 0;
+    z-index: 10;
+}
+
+.legal-nav {
+    width: 100%;
+    padding: 18px max(16px, calc((100vw - 1200px) / 2)) 16px;
+    display: flex;
+    align-items: center;
+    justify-content: space-between;
+    gap: 20px;
+    border-right: 4px solid #12212d;
+    border-bottom: 4px solid #12212d;
+    border-left: 4px solid #12212d;
+    background: linear-gradient(180deg, rgba(17, 29, 39, 0.96), rgba(31, 49, 64, 0.94));
+    backdrop-filter: blur(12px);
+    box-shadow: 0 18px 40px rgba(31, 49, 64, 0.18);
+}
+
+.brand {
+    display: inline-flex;
+    align-items: center;
+    gap: 12px;
+    color: #fff7eb;
+    font-size: 18px;
+    font-weight: 700;
+    letter-spacing: 0.03em;
+}
+
+.brand-mark {
+    width: 40px;
+    height: 40px;
+    display: grid;
+    place-items: center;
+    border-radius: 8px;
+    background: linear-gradient(135deg, var(--gold), var(--gold-soft));
+    color: #2c2215;
+    font-size: 22px;
+}
+
+.legal-nav-links {
+    display: flex;
+    align-items: center;
+    flex-wrap: wrap;
+    gap: 12px;
+    color: #ecf4fb;
+}
+
+.legal-nav-links a,
+.legal-nav-links .lang-switch {
+    display: inline-flex;
+    align-items: center;
+    justify-content: center;
+    min-height: 46px;
+    padding: 11px 16px;
+    border: 2px solid transparent;
+    background: rgba(255, 255, 255, 0.06);
+    font-weight: 700;
+    transition: transform 0.2s ease, border-color 0.2s ease;
+}
+
+.lang-switch {
+    cursor: pointer;
+    border: 2px solid rgba(231, 191, 119, 0.45);
+    color: #ecf4fb;
+    appearance: none;
+}
+
+.legal-nav-links .lang-switch {
+    min-width: 68px;
+    font: inherit;
+    background: rgba(255, 255, 255, 0.06);
+}
+
+.legal-nav-links a:hover {
+    transform: translateY(-2px);
+    border-color: rgba(231, 191, 119, 0.45);
+}
+
+.legal-nav-links .lang-switch:hover {
+    transform: translateY(-2px);
+    border-color: rgba(255, 222, 170, 0.85);
+}
+
+.legal-main {
+    width: min(980px, calc(100vw - 32px));
+    margin: 0 auto;
+    padding: 40px 0 56px;
+}
+
+.legal-hero {
+    margin-bottom: 24px;
+    padding: 34px;
+    border: 1px solid var(--line);
+    background: linear-gradient(135deg, rgba(255, 250, 242, 0.94), rgba(245, 230, 205, 0.8));
+    box-shadow: var(--shadow);
+}
+
+.legal-eyebrow {
+    margin: 0 0 12px;
+    color: var(--navy-soft);
+    text-transform: uppercase;
+    letter-spacing: 0.14em;
+    font-size: 13px;
+    font-weight: 700;
+}
+
+.legal-hero h1,
+.legal-card h2 {
+    margin-top: 0;
+    color: #182029;
+}
+
+.legal-hero h1 {
+    margin-bottom: 16px;
+    line-height: 0.98;
+    letter-spacing: -0.03em;
+    font-size: clamp(2.4rem, 4vw, 4.4rem);
+}
+
+.legal-lead,
+.legal-card p,
+.legal-list {
+    font-family: "Trebuchet MS", "Segoe UI", sans-serif;
+    color: var(--muted);
+    line-height: 1.7;
+}
+
+.legal-card {
+    margin-bottom: 20px;
+    padding: 28px 30px;
+    border: 1px solid var(--line);
+    background: rgba(255, 250, 242, 0.82);
+    box-shadow: var(--shadow);
+}
+
+.legal-note {
+    border-left: 6px solid var(--gold);
+    background: linear-gradient(135deg, rgba(255, 247, 235, 0.98), rgba(241, 221, 174, 0.3));
+}
+
+.legal-card h2 {
+    margin-bottom: 12px;
+    font-size: 1.45rem;
+}
+
+.legal-card p {
+    margin: 0;
+}
+
+.legal-card p+p,
+.legal-card p+.legal-list,
+.legal-list+p {
+    margin-top: 14px;
+}
+
+.legal-list {
+    margin: 0;
+    padding-left: 20px;
+}
+
+.legal-list li+li {
+    margin-top: 8px;
+}
+
+@media (max-width: 760px) {
+    .legal-nav {
+        padding-left: 16px;
+        padding-right: 16px;
+        flex-direction: column;
+        align-items: flex-start;
+    }
+
+    .legal-main {
+        padding-top: 28px;
+    }
+
+    .legal-hero,
+    .legal-card {
+        padding: 24px 22px;
+    }
+}

app/static/css/login.css

@@ -117,6 +117,14 @@ a {
 
 .nav-form {
     margin: 0;
+    display: flex;
+    flex-direction: row;
+    align-items: center;
+    gap: 0;
+    padding: 0;
+    background: transparent;
+    border: none;
+    color: #ecf4fb;
 }
 
 .auth-shell {
@@ -145,6 +153,67 @@ a {
     width: min(980px, 100%);
 }
 
+.settings-topbar {
+    display: flex;
+    align-items: center;
+    justify-content: space-between;
+    gap: 14px;
+    flex-wrap: wrap;
+    margin-bottom: 20px;
+}
+
+.back-link {
+    display: inline-flex;
+    align-items: center;
+    gap: 10px;
+    padding: 10px 14px;
+    border-radius: 999px;
+    background: rgba(31, 49, 64, 0.08);
+    border: 1px solid rgba(31, 49, 64, 0.12);
+    font-family: "Trebuchet MS", "Segoe UI", sans-serif;
+    font-weight: 700;
+    color: var(--navy);
+    transition: transform 0.2s ease, background 0.2s ease, border-color 0.2s ease;
+}
+
+.back-link:hover {
+    transform: translateY(-1px);
+    background: rgba(31, 49, 64, 0.12);
+    border-color: rgba(31, 49, 64, 0.18);
+}
+
+.back-link-arrow {
+    font-size: 18px;
+    line-height: 1;
+}
+
+.lang-switch,
+#logoutButton {
+    margin-top: 0;
+    min-height: 40px;
+    padding: 11px 16px;
+    font-size: 14px;
+    line-height: 1.1;
+}
+
+.lang-switch {
+    min-width: 58px;
+    background: rgba(31, 49, 64, 0.08);
+    border: 2px solid rgba(31, 49, 64, 0.18);
+    color: var(--navy);
+}
+
+.lang-switch:hover {
+    color: var(--navy);
+    background: rgba(31, 49, 64, 0.12);
+    border-color: rgba(31, 49, 64, 0.18);
+    box-shadow: none;
+}
+
+#logoutButton {
+    color: #fff7eb;
+}
+
 .settings-grid {
     display: grid;
     gap: 24px;
@@ -344,6 +413,16 @@ button:active {
         padding: 10px 14px;
     }
 
+    .settings-topbar {
+        align-items: stretch;
+    }
+
+    .back-link,
+    .lang-switch {
+        width: 100%;
+        justify-content: center;
+    }
+
     .auth-shell {
         padding: 22px 12px 28px;
     }
@@ -355,4 +434,4 @@ button:active {
     form {
         padding: 18px;
     }
-}
+}

app/static/js/index.js

@@ -1,61 +1,69 @@
+// settings for preview board
 const HERO_BOARD_SIZE = 8;
 const heroBoard = document.getElementById("heroBoard");
+
+//translation for English and German
+const AppLanguage = window.AppLanguage;
 const langSwitch = document.getElementById("langSwitch");
-const supportedLanguages = ["de", "en"];
 const initialLanguage = window.LANDING_INITIAL_LANGUAGE || "de";
+let currentLanguage = initialLanguage;
 
 const translations = {
     de: {
         "meta.title": "8-Damen- und 8-Türme Solver",
         "nav.brand": "8-Damen- und 8-Türme Solver",
         "nav.problem": "Problem",
-        "nav.features": "Features",
+        "nav.features": "Funktionen",
         "nav.journey": "Ablauf",
-        "nav.login": "Login",
-        "nav.signup": "Create Account",
+        "nav.login": "Anmelden",
+        "nav.signup": "Account erstellen",
         "hero.eyebrow": "Interaktives Lernen mit Strategie, Logik und Backtracking",
         "hero.title": "Entdecke das Acht-Damen- und Acht-Türme-Problem.",
-        "hero.text": "Diese App macht aus einem klassischen Informatik- und Mathematikproblem ein interaktives Erlebnis: Setze Damen oder Türme, verfolge den Solver Schritt fuer Schritt, miss deine Zeit und speichere clevere Zwischenstände.",
+        "hero.text": "Diese App macht aus einem klassischen Informatik- und Mathematikproblem ein interaktives Erlebnis: Setze Damen oder Türme, verfolge den Solver Schritt für Schritt, miss deine Zeit und speichere clevere Zwischenstände.",
         "hero.primaryCta": "Jetzt starten",
-        "hero.secondaryCta": "Bereits Account? Login",
+        "hero.secondaryCta": "Bereits ein Account? Anmelden",
         "hero.fact1Title": "Skalierbar",
         "hero.fact1Text": "Brettgrösse flexibel anpassen",
         "hero.fact2Title": "Schritt für Schritt",
         "hero.fact2Text": "Solver mit Animation",
-        "hero.fact3Title": "Save-Points",
+        "hero.fact3Title": "Speicherstände",
         "hero.fact3Text": "Zeit und Fortschritt behalten",
-        "hero.solverLabel": "Solver",
-        "hero.solverValue": "Backtracking live",
-        "hero.challengeLabel": "Challenge",
+        "hero.solverLabel": "Lösungshelfer",
+        "hero.solverValue": "Backtracking in Echtzeit",
+        "hero.challengeLabel": "Herausforderung",
         "hero.challengeValue": "Zeit und Schritte messen",
-        "problem.eyebrow": "Warum dieses Problem spannend ist",
-        "problem.title": "Die Acht-Damen- und Acht-Türme-Probleme sind mehr als Schachrätsel.",
-        "problem.text": "Beim Acht-Damen-Problem suchst du eine Anordnung von acht Damen auf einem Schachbrett, sodass sich keine zwei Damen schlagen. Beim Acht-Tuerme-Problem gilt dieselbe Idee für Türme, nur mit einfacheren Konfliktregeln. Beide Aufgaben zeigen, wie Mustererkennung, systematische Suche und Backtracking funktionieren.<br><br>Gerade beim Damenproblem wird schnell sichtbar, warum Strategie wichtig ist: Es gibt unzählige moegliche Platzierungen, aber nur sehr wenige wirklich gültige Loesungen. Genau das macht diese App spannend, weil man nicht nur das Ergebnis sieht, sondern auch den Weg dorthin.",
+        "problem.eyebrow": "Was ist das Acht-Damen-Problem?",
+        "problem.title": "Eine klassische schachmathematische Aufgabe mit überraschend vielen Lösungen.",
+        "problem.text": "Das Acht-Damen-Problem ist eine schachmathematische Aufgabe: Acht Damen sollen auf einem Schachbrett so aufgestellt werden, dass keine zwei Damen dieselbe Reihe, Spalte oder Diagonale teilen. Das Problem lässt sich auf beliebige Brettgrössen verallgemeinern, indem n Damen auf einem n x n-Brett platziert werden.<br><br>Für das klassische 8x8-Brett gibt es 92 Lösungen. Zählt man Stellungen, die nur durch Spiegelung oder Drehung entstehen, als gleich, bleiben 12 eindeutige Lösungen übrig.<br><br><a href=\"https://de-academic.com/dic.nsf/dewiki/13248\" target=\"_blank\" rel=\"noopener noreferrer\">Quelle: de-academic.com</a>",
         "features.eyebrow": "Was die Applikation bietet",
         "features.title": "Von der Idee bis zur gelösten Stellung.",
         "features.card1Title": "Interaktives Brett",
         "features.card1Text": "Setze Damen oder Türme direkt auf dem Brett und prüfe, ob deine Anordnung konfliktfrei ist.",
         "features.card2Title": "Solver mit Animation",
-        "features.card2Text": "Beobachte den Loesungsweg Schritt fuer Schritt und verstehe, wie Backtracking arbeitet.",
+        "features.card2Text": "Beobachte den Lösungsweg Schritt für Schritt und verstehe, wie Backtracking arbeitet.",
         "features.card3Title": "Zeit und Schritte",
         "features.card3Text": "Miss deinen Fortschritt während des Spiels und vergleiche unterschiedliche Versuche.",
-        "features.card4Title": "Save-Points",
-        "features.card4Text": "Speichere Zwischenstände mit Notizen, Zeiten und Schrittzahl fuer späteres Weiterarbeiten.",
+        "features.card4Title": "Speicherstände",
+        "features.card4Text": "Speichere Zwischenstände mit Notizen, Zeiten und Schrittzahl für späteres Weiterarbeiten.",
         "features.card5Title": "Skalierbare Bretter",
         "features.card5Text": "Passe die Brettgrösse an und erkunde die Probleme nicht nur auf dem klassischen 8x8-Brett.",
         "journey.eyebrow": "So funktioniert dein Einstieg",
         "journey.title": "In wenigen Schritten vom ersten Besuch zur eigenen Lösung.",
         "journey.step1Title": "Account erstellen",
-        "journey.step1Text": "Registriere dich und erhalte Zugang zu Dashboard, Save-Points und deinem Fortschritt.",
+        "journey.step1Text": "Registriere dich und erhalte Zugang zum Dashboard, zu Speicherständen und zu deinem Fortschritt.",
         "journey.step2Title": "Spielmodus wählen",
         "journey.step2Text": "Arbeite mit Damen oder Türmen und passe die Brettgrösse deinem Ziel an.",
-        "journey.step3Title": "Loesen oder analysieren",
-        "journey.step3Text": "Teste eigene Ideen oder lass dir die Lösung visuell vom Solver lösen lassen, dabei wird 1:1 gezeigt wie der Solver vorgeht.",
+        "journey.step3Title": "Lösen oder analysieren",
+        "journey.step3Text": "Teste eigene Ideen oder lass dir die Lösung visuell vom Solver zeigen, damit du den Lösungsweg besser nachvollziehen kannst.",
         "cta.eyebrow": "Bereit für den ersten Versuch?",
         "cta.title": "Mach aus einem bekannten Problem ein sichtbares Lernerlebnis.",
         "cta.text": "Starte mit einem Account, speichere deine Zwischenstände und finde heraus, wie schnell du eine konfliktfreie Lösung erreichst.",
-        "cta.primaryCta": "Create Account",
-        "cta.secondaryCta": "Login"
+        "cta.primaryCta": "Account erstellen",
+        "cta.secondaryCta": "Anmelden",
+        "footerText": "Schulprojekt rund um das Acht-Damen- und Acht-Türme-Problem.",
+        "footerPrivacy": "Datenschutzerklärung",
+        "footerImprint": "Impressum",
+        "footerNavAria": "Rechtliche Hinweise"
     },
     en: {
         "meta.title": "8 Queens and 8 Rooks Solver",
@@ -63,13 +71,13 @@ const translations = {
         "nav.problem": "Problem",
         "nav.features": "Features",
         "nav.journey": "Journey",
-        "nav.login": "Login",
+        "nav.login": "Sign in",
         "nav.signup": "Create Account",
         "hero.eyebrow": "Interactive learning with strategy, logic, and backtracking",
         "hero.title": "Discover the Eight Queens and Eight Rooks puzzle.",
         "hero.text": "This app turns a classic computer science and mathematics problem into an interactive experience: place queens or rooks, follow the solver step by step, track your time, and save clever checkpoints.",
         "hero.primaryCta": "Get Started",
-        "hero.secondaryCta": "Already have an account? Login",
+        "hero.secondaryCta": "Already have an account? Sign in",
         "hero.fact1Title": "Scalable",
         "hero.fact1Text": "Adjust the board size freely",
         "hero.fact2Title": "Step by step",
@@ -80,9 +88,9 @@ const translations = {
         "hero.solverValue": "Backtracking in motion",
         "hero.challengeLabel": "Challenge",
         "hero.challengeValue": "Measure time and steps",
-        "problem.eyebrow": "Why this puzzle matters",
-        "problem.title": "The Eight Queens and Eight Rooks problems are more than chess puzzles.",
-        "problem.text": "In the Eight Queens problem, you search for a way to place eight queens on a chessboard so that no two queens can attack each other. The Eight Rooks problem follows the same idea for rooks, but with simpler conflict rules. Both tasks show how pattern recognition, systematic search, and backtracking work.<br><br>The queens puzzle quickly makes it obvious why strategy matters: there are countless possible placements, but only a few truly valid solutions. That is what makes this app interesting, because you do not just see the result, you also see the path to it.",
+        "problem.eyebrow": "What is the Eight Queens problem?",
+        "problem.title": "A classic chess-related math puzzle with surprisingly many solutions.",
+        "problem.text": "The Eight Queens problem is a chess-related mathematical puzzle: eight queens must be placed on a chessboard so that no two queens share the same row, column, or diagonal. The idea can be generalized to boards of any size by placing n queens on an n x n board.<br><br>On the classic 8x8 board there are 92 solutions. If positions that only differ by reflection or rotation are counted as the same, 12 unique solutions remain.<br><br><a href=\"https://de-academic.com/dic.nsf/dewiki/13248\" target=\"_blank\" rel=\"noopener noreferrer\">Source: de-academic.com</a>",
         "features.eyebrow": "What the application offers",
         "features.title": "From the first idea to a solved position.",
         "features.card1Title": "Interactive board",
@@ -107,10 +115,51 @@ const translations = {
         "cta.title": "Turn a famous puzzle into a visible learning experience.",
         "cta.text": "Start with an account, save your checkpoints, and find out how quickly you can reach a conflict-free solution.",
         "cta.primaryCta": "Create Account",
-        "cta.secondaryCta": "Login"
+        "cta.secondaryCta": "Sign in",
+        "footerText": "School project about the Eight Queens and Eight Rooks problem.",
+        "footerPrivacy": "Privacy Policy",
+        "footerImprint": "Imprint",
+        "footerNavAria": "Legal information"
     }
 };
 
+function t(key) {
+    return translations[currentLanguage]?.[key] ?? null;
+}
+
+function applyTranslations(language) {
+    currentLanguage = language;
+
+    AppLanguage.applyTranslations({
+        translate: (key) => t(key),
+        allowHtml: (element, translatedText) => element.tagName === "TITLE" || String(translatedText).includes("<br"),
+        attributeMappings: [
+            {
+                selector: "[data-i18n-aria-label]",
+                datasetKey: "i18nAriaLabel",
+                attribute: "aria-label"
+            }
+        ]
+    });
+}
+
+const languageController = AppLanguage.createController({
+    button: langSwitch,
+    defaultLanguage: initialLanguage,
+    onApply(language, helpers) {
+        applyTranslations(language);
+        helpers.updateLanguageSwitch({
+            ariaLabel: language === "de" ? "Switch language to English" : "Sprache auf Deutsch wechseln",
+            title: language === "de" ? "Switch to English" : "Zu Deutsch wechseln"
+        });
+    }
+});
+
+languageController.init();
+
+// ----------------------------------------------------------------------------------------
+
+// simple pattern for preview board
 const queenPatterns = [
     [0, 4, 7, 5, 2, 6, 1, 3],
     [1, 3, 5, 7, 2, 0, 6, 4],
@@ -119,69 +168,6 @@ const queenPatterns = [
 
 let currentPatternIndex = 0;
 
-function normalizeLanguage(language) {
-    const shortLanguage = String(language || "").trim().slice(0, 2).toLowerCase();
-    return supportedLanguages.includes(shortLanguage) ? shortLanguage : "de";
-}
-
-function getStoredLanguage() {
-    try {
-        return window.localStorage.getItem("preferredLanguage");
-    } catch (error) {
-        return null;
-    }
-}
-
-function storeLanguage(language) {
-    try {
-        window.localStorage.setItem("preferredLanguage", language);
-    } catch (error) {
-        return;
-    }
-}
-
-function detectBrowserLanguage() {
-    const browserLanguage = navigator.language || navigator.userLanguage || initialLanguage;
-    return normalizeLanguage(browserLanguage);
-}
-
-function setLanguage(language) {
-    const resolvedLanguage = normalizeLanguage(language);
-    const dictionary = translations[resolvedLanguage];
-    const i18nElements = document.querySelectorAll("[data-i18n]");
-
-    document.documentElement.lang = resolvedLanguage;
-    document.body.dataset.language = resolvedLanguage;
-
-    i18nElements.forEach((element) => {
-        const key = element.dataset.i18n;
-        const translatedText = dictionary[key];
-
-        if (!translatedText) {
-            return;
-        }
-
-        if (element.tagName === "TITLE" || translatedText.includes("<br")) {
-            element.innerHTML = translatedText;
-            return;
-        }
-
-        element.textContent = translatedText;
-    });
-
-    if (langSwitch) {
-        langSwitch.textContent = resolvedLanguage.toUpperCase();
-        langSwitch.setAttribute("aria-label", resolvedLanguage === "de" ? "Switch language to English" : "Sprache auf Deutsch wechseln");
-        langSwitch.title = resolvedLanguage === "de" ? "Switch to English" : "Zu Deutsch wechseln";
-    }
-
-    storeLanguage(resolvedLanguage);
-}
-
-function getPreferredLanguage() {
-    return normalizeLanguage(getStoredLanguage() || detectBrowserLanguage() || initialLanguage);
-}
-
 function createHeroBoard() {
     if (!heroBoard) {
         return;
@@ -222,16 +208,8 @@ function rotatePattern() {
     applyPattern(queenPatterns[currentPatternIndex]);
 }
 
-if (langSwitch) {
-    langSwitch.addEventListener("click", () => {
-        const nextLanguage = document.documentElement.lang === "de" ? "en" : "de";
-        setLanguage(nextLanguage);
-    });
-}
-
 createHeroBoard();
 applyPattern(queenPatterns[currentPatternIndex]);
-setLanguage(getPreferredLanguage());
 
 if (heroBoard) {
     window.setInterval(rotatePattern, 2200);

app/static/js/language.js

@@ -0,0 +1,261 @@
+// handels the language translation
+
+(function attachAppLanguage(window, document) {
+    const DEFAULT_LANGUAGE = "de";
+    const DEFAULT_STORAGE_KEY = "preferredLanguage";
+    const DEFAULT_SUPPORTED_LANGUAGES = ["de", "en"];
+
+    function resolveSupportedLanguages(supportedLanguages = DEFAULT_SUPPORTED_LANGUAGES) {
+        const normalizedLanguages = Array.isArray(supportedLanguages)
+            ? supportedLanguages
+                .map((language) => String(language || "").trim().slice(0, 2).toLowerCase())
+                .filter(Boolean)
+            : [];
+
+        return normalizedLanguages.length > 0 ? normalizedLanguages : DEFAULT_SUPPORTED_LANGUAGES.slice();
+    }
+
+    function normalizeLanguage(
+        language,
+        {
+            supportedLanguages = DEFAULT_SUPPORTED_LANGUAGES,
+            defaultLanguage = DEFAULT_LANGUAGE
+        } = {}
+    ) {
+        const normalizedSupportedLanguages = resolveSupportedLanguages(supportedLanguages);
+        const normalizedDefaultLanguage = normalizedSupportedLanguages.includes(defaultLanguage)
+            ? defaultLanguage
+            : normalizedSupportedLanguages[0] || DEFAULT_LANGUAGE;
+        const shortLanguage = String(language || "").trim().slice(0, 2).toLowerCase();
+
+        return normalizedSupportedLanguages.includes(shortLanguage) ? shortLanguage : normalizedDefaultLanguage;
+    }
+
+    function getStoredLanguage({ storageKey = DEFAULT_STORAGE_KEY } = {}) {
+        try {
+            return window.localStorage.getItem(storageKey);
+        } catch (error) {
+            return null;
+        }
+    }
+
+    function storeLanguage(language, { storageKey = DEFAULT_STORAGE_KEY } = {}) {
+        try {
+            window.localStorage.setItem(storageKey, language);
+        } catch (error) {
+            return;
+        }
+    }
+
+    function detectBrowserLanguage(options = {}) {
+        return normalizeLanguage(navigator.language || navigator.userLanguage || options.defaultLanguage, options);
+    }
+
+    function getPreferredLanguage(
+        {
+            supportedLanguages = DEFAULT_SUPPORTED_LANGUAGES,
+            defaultLanguage = DEFAULT_LANGUAGE,
+            storageKey = DEFAULT_STORAGE_KEY,
+            fallbackLanguage = defaultLanguage
+        } = {}
+    ) {
+        return normalizeLanguage(
+            getStoredLanguage({ storageKey }) || detectBrowserLanguage({ supportedLanguages, defaultLanguage }) || fallbackLanguage,
+            {
+                supportedLanguages,
+                defaultLanguage: fallbackLanguage
+            }
+        );
+    }
+
+    function getNextLanguage(language, supportedLanguages = DEFAULT_SUPPORTED_LANGUAGES) {
+        const normalizedSupportedLanguages = resolveSupportedLanguages(supportedLanguages);
+        const currentLanguage = normalizeLanguage(language, {
+            supportedLanguages: normalizedSupportedLanguages,
+            defaultLanguage: normalizedSupportedLanguages[0]
+        });
+        const currentIndex = normalizedSupportedLanguages.indexOf(currentLanguage);
+
+        if (currentIndex === -1 || normalizedSupportedLanguages.length < 2) {
+            return currentLanguage;
+        }
+
+        return normalizedSupportedLanguages[(currentIndex + 1) % normalizedSupportedLanguages.length];
+    }
+
+    function setDocumentLanguage(language) {
+        if (document.documentElement) {
+            document.documentElement.lang = language;
+        }
+
+        if (document.body) {
+            document.body.dataset.language = language;
+        }
+    }
+
+    function applyTextTranslations({
+        translate,
+        selector = "[data-i18n]",
+        allowHtml = () => false
+    } = {}) {
+        if (typeof translate !== "function") {
+            return;
+        }
+
+        document.querySelectorAll(selector).forEach((element) => {
+            const key = element.dataset.i18n;
+            const translatedText = translate(key, element);
+
+            if (translatedText === undefined || translatedText === null) {
+                return;
+            }
+
+            if (allowHtml(element, translatedText, key)) {
+                element.innerHTML = String(translatedText);
+                return;
+            }
+
+            element.textContent = String(translatedText);
+        });
+    }
+
+    function applyAttributeTranslations({
+        translate,
+        mappings = []
+    } = {}) {
+        if (typeof translate !== "function") {
+            return;
+        }
+
+        mappings.forEach(({ selector, datasetKey, attribute }) => {
+            document.querySelectorAll(selector).forEach((element) => {
+                const key = element.dataset[datasetKey];
+                const translatedText = translate(key, element, attribute);
+
+                if (translatedText === undefined || translatedText === null) {
+                    return;
+                }
+
+                element.setAttribute(attribute, String(translatedText));
+            });
+        });
+    }
+
+    function applyTranslations({
+        translate,
+        selector = "[data-i18n]",
+        allowHtml,
+        attributeMappings = []
+    } = {}) {
+        applyTextTranslations({ translate, selector, allowHtml });
+        applyAttributeTranslations({ translate, mappings: attributeMappings });
+    }
+
+    function updateLanguageSwitch(
+        button,
+        {
+            language,
+            label = String(language || "").toUpperCase(),
+            ariaLabel,
+            title
+        } = {}
+    ) {
+        if (!button) {
+            return;
+        }
+
+        button.textContent = label;
+
+        if (ariaLabel !== undefined) {
+            button.setAttribute("aria-label", ariaLabel);
+        }
+
+        if (title !== undefined) {
+            button.title = title;
+        }
+    }
+
+    function createController({
+        button = document.getElementById("langSwitch"),
+        defaultLanguage = DEFAULT_LANGUAGE,
+        supportedLanguages = DEFAULT_SUPPORTED_LANGUAGES,
+        storageKey = DEFAULT_STORAGE_KEY,
+        onApply = () => { }
+    } = {}) {
+        const options = {
+            defaultLanguage,
+            supportedLanguages,
+            storageKey
+        };
+
+        let currentLanguage = normalizeLanguage(defaultLanguage, options);
+
+        function apply(language, source = "apply") {
+            currentLanguage = normalizeLanguage(language, options);
+            setDocumentLanguage(currentLanguage);
+
+            onApply(currentLanguage, {
+                source,
+                button,
+                applyTranslations,
+                updateLanguageSwitch: (switchOptions = {}) => updateLanguageSwitch(button, {
+                    language: currentLanguage,
+                    ...switchOptions
+                }),
+                getNextLanguage: () => getNextLanguage(currentLanguage, supportedLanguages),
+                normalizeLanguage: (value) => normalizeLanguage(value, options)
+            });
+
+            storeLanguage(currentLanguage, { storageKey });
+            return currentLanguage;
+        }
+
+        function toggle() {
+            return apply(getNextLanguage(currentLanguage, supportedLanguages), "toggle");
+        }
+
+        function init(initialLanguage = getPreferredLanguage({
+            supportedLanguages,
+            defaultLanguage,
+            storageKey,
+            fallbackLanguage: defaultLanguage
+        })) {
+            if (button) {
+                button.addEventListener("click", toggle);
+            }
+
+            return apply(initialLanguage, "init");
+        }
+
+        return {
+            apply,
+            getCurrentLanguage: () => currentLanguage,
+            getPreferredLanguage: (fallbackLanguage = defaultLanguage) => getPreferredLanguage({
+                supportedLanguages,
+                defaultLanguage,
+                storageKey,
+                fallbackLanguage
+            }),
+            init,
+            toggle
+        };
+    }
+
+    window.AppLanguage = {
+        DEFAULT_LANGUAGE,
+        DEFAULT_STORAGE_KEY,
+        DEFAULT_SUPPORTED_LANGUAGES: DEFAULT_SUPPORTED_LANGUAGES.slice(),
+        applyAttributeTranslations,
+        applyTextTranslations,
+        applyTranslations,
+        createController,
+        detectBrowserLanguage,
+        getNextLanguage,
+        getPreferredLanguage,
+        getStoredLanguage,
+        normalizeLanguage,
+        setDocumentLanguage,
+        storeLanguage,
+        updateLanguageSwitch
+    };
+})(window, document);

app/static/js/legal.js

@@ -0,0 +1,174 @@
+//translation for English and German
+
+const AppLanguage = window.AppLanguage;
+const langSwitch = document.getElementById("langSwitch");
+const legalPage = document.body.dataset.legalPage;
+let currentLanguage = AppLanguage.DEFAULT_LANGUAGE;
+
+const translations = {
+    de: {
+        common: {
+            navBrand: "8-Damen- und 8-Türme Solver",
+            navHome: "Startseite",
+            navDashboard: "Dashboard",
+            navLogin: "Login",
+            heroEyebrow: "Rechtliche Hinweise",
+            footerText: "Schulprojekt rund um das Acht-Damen- und Acht-Türme-Problem.",
+            footerPrivacy: "Datenschutzerklärung",
+            footerImprint: "Impressum",
+            footerNavAria: "Rechtliche Hinweise",
+            languageSwitchAria: "Sprache wechseln"
+        },
+        imprint: {
+            pageTitle: "Impressum",
+            heroTitle: "Impressum",
+            contactTitle: "Kontakt",
+            contactName: "Jérôme Bachmann",
+            contactEmailLabel: "E-Mail:",
+            projectResponsibilityTitle: "Projektverantwortung",
+            projectResponsibilityText: "Dieses Webprojekt wurde im Rahmen eines Schulprojekts zum Acht-Damen- und Acht-Türme-Problem erstellt. Inhaltlich verantwortlich ist die jeweils oben genannte verantwortliche Stelle.",
+            contentLiabilityTitle: "Haftung für Inhalte",
+            contentLiabilityText: "Die Inhalte dieser Website wurden mit Sorgfalt erstellt. Für die Richtigkeit, Vollständigkeit und Aktualität der Inhalte kann jedoch keine Gewähr übernommen werden. Bei Bekanntwerden von Rechtsverletzungen werden entsprechende Inhalte umgehend überarbeitet oder entfernt.",
+            linksLiabilityTitle: "Haftung für Links",
+            linksLiabilityText: "Diese Website kann Links zu externen Angeboten enthalten. Für deren Inhalte sind ausschliesslich die jeweiligen Betreiber verantwortlich. Eine permanente inhaltliche Kontrolle verlinkter Seiten ist ohne konkrete Anhaltspunkte einer Rechtsverletzung nicht zumutbar.",
+            versionTitle: "Stand",
+            versionText: "Stand dieser Vorlage: April 2026"
+        },
+        privacy: {
+            pageTitle: "Datenschutzerklärung",
+            heroTitle: "Datenschutzerklärung",
+            heroLead: "Diese Seite beschreibt, welche personenbezogenen Daten im Rahmen dieses Schulprojekts verarbeitet werden.",
+            dataProcessedTitle: "1. Welche Daten verarbeitet werden",
+            dataProcessedText: "Im Rahmen der Nutzung dieser Webanwendung können insbesondere folgende Daten verarbeitet werden:",
+            dataProcessedItem1: "Benutzername und verschlüsseltes Passwort bei der Registrierung und beim Login",
+            dataProcessedItem2: "Daten zur Zwei-Faktor-Authentifizierung, falls diese freiwillig aktiviert wird",
+            dataProcessedItem3: "gespeicherte Spielstände, Notizen, Schrittzahlen, Zeiten und Favoriten",
+            dataProcessedItem4: "technische Verbindungsdaten, die durch den Server oder das Hosting entstehen koennen",
+            processingPurposeTitle: "3. Zweck der Verarbeitung",
+            processingPurposeText: "Die Verarbeitung erfolgt, um die Funktionen dieser Anwendung bereitzustellen. Dazu gehoeren insbesondere:",
+            processingPurposeItem1: "Erstellung und Verwaltung von Benutzerkonten",
+            processingPurposeItem2: "sicherer Login in das persönliche Dashboard",
+            processingPurposeItem3: "optionale Absicherung des Kontos per Authenticator-App",
+            processingPurposeItem4: "Speichern und Laden von Spielständen",
+            processingPurposeItem5: "technischer Betrieb, Fehleranalyse und Missbrauchsschutz",
+            legalBasisTitle: "4. Rechtsgrundlage",
+            legalBasisText: "Soweit personenbezogene Daten verarbeitet werden, erfolgt dies in der Regel zur Bereitstellung der Anwendung und ihrer Funktionen sowie aufgrund des berechtigten Interesses an einem sicheren und funktionsfähigen Webangebot. Falls eine ausdrückliche Einwilligung erforderlich ist, wird diese gesondert eingeholt.",
+            storageTitle: "5. Speicherung und Löschung",
+            storageText: "Personenbezogene Daten werden nur so lange gespeichert, wie sie für den jeweiligen Zweck benötigt werden. Benutzerkonten und zugehörige Spielstände bleiben grundsätzlich gespeichert, bis sie gelöscht oder für das Projekt nicht mehr benötigt werden.",
+            thirdPartyTitle: "6. Weitergabe an Dritte",
+            thirdPartyText: "Eine Weitergabe personenbezogener Daten erfolgt nur, wenn dies für den Betrieb der Anwendung erforderlich ist, etwa durch einen Hosting-Anbieter oder technische Dienstleister. Ansonsten werden keine Daten weitergegeben.",
+            rightsTitle: "7. Rechte betroffener Personen",
+            rightsText: "Betroffene Personen haben im Rahmen des anwendbaren Datenschutzrechts insbesondere das Recht auf:",
+            rightsItem1: "Auskunft über die verarbeiteten personenbezogenen Daten",
+            rightsItem2: "Berichtigung unrichtiger Daten",
+            rightsItem3: "Löschung oder Einschränkung der Verarbeitung",
+            rightsItem4: "Widerspruch gegen die Verarbeitung",
+            rightsItem5: "Herausgabe der bereitgestellten Daten, soweit anwendbar",
+            securityTitle: "8. Datensicherheit",
+            securityText: "Es werden technische und organisatorische Massnahmen getroffen, um gespeicherte Daten vor Verlust, Missbrauch oder unberechtigtem Zugriff zu schützen. Dazu gehoeren insbesondere passwortgeschützte Konten und die Möglichkeit, Zwei-Faktor-Authentifizierung zu aktivieren.",
+            versionTitle: "9. Stand",
+            versionText: "Stand dieser Vorlage: April 2026"
+        }
+    },
+    en: {
+        common: {
+            navBrand: "8 Queens and 8 Rooks Solver",
+            navHome: "Home",
+            navDashboard: "Dashboard",
+            navLogin: "Login",
+            heroEyebrow: "Legal information",
+            footerText: "School project about the Eight Queens and Eight Rooks problem.",
+            footerPrivacy: "Privacy Policy",
+            footerImprint: "Imprint",
+            footerNavAria: "Legal information",
+            languageSwitchAria: "Switch language"
+        },
+        imprint: {
+            pageTitle: "Imprint",
+            heroTitle: "Imprint",
+            contactTitle: "Contact",
+            contactName: "Jérôme Bachmann",
+            contactEmailLabel: "Email:",
+            projectResponsibilityTitle: "Project responsibility",
+            projectResponsibilityText: "This web project was created as part of a school project on the Eight Queens and Eight Rooks problem. The entity named above is responsible for the content.",
+            contentLiabilityTitle: "Liability for content",
+            contentLiabilityText: "The content of this website was created with care. However, no guarantee can be given for the accuracy, completeness, or timeliness of the content. If legal violations become known, the relevant content will be revised or removed without delay.",
+            linksLiabilityTitle: "Liability for links",
+            linksLiabilityText: "This website may contain links to external offers. Their content is the sole responsibility of the respective operators. Permanent monitoring of linked pages is not reasonable without concrete indications of a legal violation.",
+            versionTitle: "Version",
+            versionText: "Version of this template: April 2026"
+        },
+        privacy: {
+            pageTitle: "Privacy Policy",
+            heroTitle: "Privacy Policy",
+            heroLead: "This page describes which personal data is processed as part of this school project.",
+            dataProcessedTitle: "1. Which data is processed",
+            dataProcessedText: "When using this web application, the following data in particular may be processed:",
+            dataProcessedItem1: "username and encrypted password during registration and login",
+            dataProcessedItem2: "two-factor authentication data if this feature is activated voluntarily",
+            dataProcessedItem3: "saved game states, notes, step counts, times, and favorites",
+            dataProcessedItem4: "technical connection data that may arise through the server or hosting",
+            processingPurposeTitle: "3. Purpose of processing",
+            processingPurposeText: "The processing is carried out to provide the functions of this application. This includes in particular:",
+            processingPurposeItem1: "creating and managing user accounts",
+            processingPurposeItem2: "secure login to the personal dashboard",
+            processingPurposeItem3: "optional account protection using an authenticator app",
+            processingPurposeItem4: "saving and loading game states",
+            processingPurposeItem5: "technical operation, error analysis, and abuse prevention",
+            legalBasisTitle: "4. Legal basis",
+            legalBasisText: "Where personal data is processed, this is generally done to provide the application and its functions, as well as on the basis of the legitimate interest in a secure and functional web offering. If explicit consent is required, it will be obtained separately.",
+            storageTitle: "5. Storage and deletion",
+            storageText: "Personal data is stored only as long as it is needed for the respective purpose. User accounts and related game states generally remain stored until they are deleted or are no longer needed for the project.",
+            thirdPartyTitle: "6. Disclosure to third parties",
+            thirdPartyText: "Personal data is shared only if this is necessary for operating the application, for example through a hosting provider or technical service providers. Otherwise, no data is shared.",
+            rightsTitle: "7. Rights of data subjects",
+            rightsText: "Within the framework of applicable data protection law, data subjects have in particular the right to:",
+            rightsItem1: "information about the personal data being processed",
+            rightsItem2: "correction of incorrect data",
+            rightsItem3: "deletion of data or restriction of processing",
+            rightsItem4: "object to the processing",
+            rightsItem5: "receive the data that has been provided, where applicable",
+            securityTitle: "8. Data security",
+            securityText: "Technical and organizational measures are taken to protect stored data against loss, misuse, or unauthorized access. These include password-protected accounts and the option to enable two-factor authentication.",
+            versionTitle: "9. Version",
+            versionText: "Version of this template: April 2026"
+        }
+    }
+};
+
+function t(key) {
+    const commonTranslation = translations[currentLanguage]?.common?.[key];
+
+    if (commonTranslation) {
+        return commonTranslation;
+    }
+
+    return translations[currentLanguage]?.[legalPage]?.[key] ?? null;
+}
+
+function applyTranslations() {
+    AppLanguage.applyTranslations({
+        translate: (key) => t(key),
+        attributeMappings: [
+            {
+                selector: "[data-i18n-aria-label]",
+                datasetKey: "i18nAriaLabel",
+                attribute: "aria-label"
+            }
+        ]
+    });
+}
+
+const languageController = AppLanguage.createController({
+    button: langSwitch,
+    onApply(language, helpers) {
+        currentLanguage = language;
+        applyTranslations();
+        helpers.updateLanguageSwitch({
+            ariaLabel: t("languageSwitchAria") || "Sprache wechseln",
+            title: language === "de" ? "Switch to English" : "Zu Deutsch wechseln"
+        });
+    }
+});
+
+languageController.init();

app/static/js/login.js

@@ -1,5 +1,205 @@
+//translation for English and German
+
+const AppLanguage = window.AppLanguage;
+const langSwitch = document.getElementById("langSwitch");
+
+const translations = {
+    de: {
+        pageTitle: "Login-Einstellungen",
+        navBrand: "8-Damen- und 8-Türme Solver",
+        navLogin: "Anmelden",
+        navRegister: "Account erstellen",
+        navDashboard: "Dashboard",
+        navSettings: "Login-Einstellungen",
+        navLogout: "Logout",
+        backToDashboard: "Zurück zum Dashboard",
+        backToDashboardAria: "Zurück zum Dashboard",
+        languageSwitchAria: "Sprache wechseln",
+        settingsTitle: "Login-Einstellungen",
+        settingsSubtitle: "Verwalte die Authenticator-App-2FA und dein Passwort, ohne den Registrierungsablauf zu ändern.",
+        twoFactorTitle: "Authenticator-App-2FA",
+        twoFactorEnabledHint: "2FA ist für dieses Konto aktuell aktiviert.",
+        twoFactorEnabledAppHint: "Nutze Google Authenticator, Microsoft Authenticator, Authy oder eine andere TOTP-App, um deine 6-stelligen Login-Codes zu generieren.",
+        disableTwoFactorButton: "2FA deaktivieren",
+        disableTwoFactorLoading: "2FA wird deaktiviert...",
+        finishSetupTitle: "2FA-Einrichtung abschließen",
+        finishSetupHint: "Scanne diesen QR-Code mit deiner Authenticator-App und gib danach den aktuellen 6-stelligen Code zur Bestätigung ein.",
+        scanFallbackHint: "Wenn das Scannen nicht funktioniert, kannst du den manuellen Einrichtungsschlüssel unten verwenden.",
+        manualSetupKey: "Manueller Einrichtungsschlüssel",
+        setupUriLabel: "Einrichtungs-URI",
+        setupUriHint: "Diese URI wird für den QR-Setup verwendet und kann als Fallback für kompatible Apps kopiert werden.",
+        authenticatorCodeLabel: "Authenticator-Code",
+        confirmAndEnableButton: "Bestätigen und aktivieren",
+        confirmAndEnableLoading: "2FA wird aktiviert...",
+        cancelSetupTitle: "Einrichtung abbrechen",
+        cancelSetupHint: "Brich die aktuelle Authenticator-Einrichtung ab, wenn du mit einem neuen Schlüssel neu starten möchtest.",
+        cancelSetupButton: "Einrichtung abbrechen",
+        startSetupHint: "Schütze dein Konto mit 6-stelligen Codes aus einer Authenticator-App.",
+        startSetupHintFollowup: "Nach dem Start der Einrichtung erhältst du einen QR-Code zum Scannen und bestätigst dann einmal mit einem aktuellen Code.",
+        startSetupButton: "Einrichtung starten",
+        startSetupLoading: "Einrichtung wird gestartet...",
+        changePasswordTitle: "Passwort ändern",
+        currentPasswordLabel: "Aktuelles Passwort",
+        newPasswordLabel: "Neues Passwort",
+        confirmPasswordLabel: "Neues Passwort bestätigen",
+        updatePasswordButton: "Passwort aktualisieren",
+        updatePasswordLoading: "Passwort wird aktualisiert...",
+        qrLoadError: "QR-Vorschau konnte nicht geladen werden.",
+        footerText: "Schulprojekt rund um das Acht-Damen- und Acht-Türme-Problem.",
+        footerPrivacy: "Datenschutzerklärung",
+        footerImprint: "Impressum",
+        footerNavAria: "Rechtliche Hinweise"
+    },
+    en: {
+        pageTitle: "Login Settings",
+        navBrand: "8 Queens and 8 Rooks Solver",
+        navLogin: "Login",
+        navRegister: "Create account",
+        navDashboard: "Dashboard",
+        navSettings: "Login settings",
+        navLogout: "Logout",
+        backToDashboard: "Back to dashboard",
+        backToDashboardAria: "Back to dashboard",
+        languageSwitchAria: "Switch language",
+        settingsTitle: "Login settings",
+        settingsSubtitle: "Manage authenticator app 2FA and your password without changing the registration flow.",
+        twoFactorTitle: "Authenticator app 2FA",
+        twoFactorEnabledHint: "2FA is currently enabled for this account.",
+        twoFactorEnabledAppHint: "Use Google Authenticator, Microsoft Authenticator, Authy, or another TOTP app to generate your 6-digit login codes.",
+        disableTwoFactorButton: "Disable 2FA",
+        disableTwoFactorLoading: "Disabling 2FA...",
+        finishSetupTitle: "Finish 2FA setup",
+        finishSetupHint: "Scan this QR code with your authenticator app, then enter the current 6-digit code to confirm.",
+        scanFallbackHint: "If scanning does not work, you can still use the manual setup key below.",
+        manualSetupKey: "Manual setup key",
+        setupUriLabel: "Setup URI",
+        setupUriHint: "This URI is used to generate the QR setup and can be copied as a fallback for compatible apps.",
+        authenticatorCodeLabel: "Authenticator code",
+        confirmAndEnableButton: "Confirm and enable",
+        confirmAndEnableLoading: "Enabling 2FA...",
+        cancelSetupTitle: "Cancel setup",
+        cancelSetupHint: "Cancel the current authenticator setup if you want to restart with a new secret.",
+        cancelSetupButton: "Cancel setup",
+        startSetupHint: "Protect your account with 6-digit codes from an authenticator app.",
+        startSetupHintFollowup: "After starting setup, you will get a QR code to scan and then confirm once with a live code.",
+        startSetupButton: "Start setup",
+        startSetupLoading: "Starting setup...",
+        changePasswordTitle: "Change password",
+        currentPasswordLabel: "Current password",
+        newPasswordLabel: "New password",
+        confirmPasswordLabel: "Confirm new password",
+        updatePasswordButton: "Update password",
+        updatePasswordLoading: "Updating password...",
+        qrLoadError: "QR preview could not be loaded.",
+        footerText: "School project about the Eight Queens and Eight Rooks problem.",
+        footerPrivacy: "Privacy Policy",
+        footerImprint: "Imprint",
+        footerNavAria: "Legal information"
+    }
+};
+
+const serverMessageTranslations = {
+    de: {
+        "Authenticator app 2FA is already enabled.": "Authenticator-App-2FA ist bereits aktiviert.",
+        "Add the secret to your authenticator app, then confirm it with the current 6-digit code.": "Füge den Schlüssel zu deiner Authenticator-App hinzu und bestätige ihn dann mit dem aktuellen 6-stelligen Code.",
+        "Start the authenticator setup first.": "Starte zuerst die Authenticator-Einrichtung.",
+        "Invalid authenticator code. Please try the current code again.": "Ungültiger Authenticator-Code. Bitte versuche den aktuellen Code erneut.",
+        "Authenticator app 2FA enabled.": "Authenticator-App-2FA wurde aktiviert.",
+        "Authenticator app setup cancelled.": "Die Einrichtung der Authenticator-App wurde abgebrochen.",
+        "Authenticator app 2FA disabled.": "Authenticator-App-2FA wurde deaktiviert.",
+        "Your current password is incorrect.": "Dein aktuelles Passwort ist falsch.",
+        "The new passwords do not match.": "Die neuen Passwörter stimmen nicht überein.",
+        "Password updated successfully.": "Das Passwort wurde erfolgreich aktualisiert.",
+        "Unknown settings action.": "Unbekannte Einstellungsaktion."
+    },
+    en: {}
+};
+
+let currentLanguage = AppLanguage.DEFAULT_LANGUAGE;
+
+function t(key) {
+    return translations[currentLanguage]?.[key] ?? translations.en[key] ?? key;
+}
+
+function translateServerMessage(message) {
+    const originalMessage = String(message || "").trim();
+
+    if (!originalMessage || currentLanguage === "en") {
+        return originalMessage;
+    }
+
+    const exactMatch = serverMessageTranslations[currentLanguage]?.[originalMessage];
+
+    if (exactMatch) {
+        return exactMatch;
+    }
+
+    const minLengthMatch = originalMessage.match(/^Password must be at least (\d+) characters long\.$/);
+
+    if (minLengthMatch) {
+        return `Das Passwort muss mindestens ${minLengthMatch[1]} Zeichen lang sein.`;
+    }
+
+    const maxLengthMatch = originalMessage.match(/^Password must be at most (\d+) characters long\.$/);
+
+    if (maxLengthMatch) {
+        return `Das Passwort darf höchstens ${maxLengthMatch[1]} Zeichen lang sein.`;
+    }
+
+    return originalMessage;
+}
+
+function applyTextTranslations() {
+    AppLanguage.applyTranslations({
+        translate: (key) => t(key),
+        attributeMappings: [
+            {
+                selector: "[data-i18n-aria-label]",
+                datasetKey: "i18nAriaLabel",
+                attribute: "aria-label"
+            },
+            {
+                selector: "[data-i18n-loading-label]",
+                datasetKey: "i18nLoadingLabel",
+                attribute: "data-loading-label"
+            }
+        ]
+    });
+
+    document.querySelectorAll("[data-i18n-loading-label]").forEach((element) => {
+        if (element.dataset.loadingLabelApplied === "true") {
+            element.textContent = element.dataset.loadingLabel;
+        }
+    });
+
+    document.querySelectorAll(".message").forEach((element) => {
+        if (!element.dataset.originalText) {
+            element.dataset.originalText = element.textContent.trim();
+        }
+
+        element.textContent = translateServerMessage(element.dataset.originalText);
+    });
+}
+
+const languageController = AppLanguage.createController({
+    button: langSwitch,
+    onApply(language, helpers) {
+        currentLanguage = language;
+        applyTextTranslations();
+        helpers.updateLanguageSwitch({
+            ariaLabel: t("languageSwitchAria"),
+            title: currentLanguage === "de" ? "Switch to English" : "Zu Deutsch wechseln"
+        });
+    }
+});
+
+languageController.init();
+
+// -----------------------------------------------------------------------------------------------
+
 const magneticButtons = document.querySelectorAll(".magnetic");
 
+// magnetic button effect for desktop user
 magneticButtons.forEach((button) => {
     button.addEventListener("mousemove", (event) => {
         const rect = button.getBoundingClientRect();
@@ -37,8 +237,8 @@ document.querySelectorAll("form").forEach((form) => {
 
         if (loadingLabel) {
             submitter.dataset.loadingLabelApplied = "true";
-            submitter.dataset.originalLabel = submitter.innerText;
-            submitter.innerText = loadingLabel;
+            submitter.dataset.originalLabel = submitter.textContent;
+            submitter.textContent = loadingLabel;
             submitter.style.opacity = "0.7";
         }
     });
@@ -52,7 +252,7 @@ document.querySelectorAll(".qr-code[data-qr-value]").forEach((container) => {
     }
 
     if (typeof window.QRCode !== "function") {
-        container.textContent = "QR preview could not be loaded.";
+        container.textContent = t("qrLoadError");
         return;
     }
 

app/templates/dashboard.html

@@ -4,35 +4,37 @@
 <head>
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
-    <title>Dashboard</title>
+    <title data-i18n="pageTitle">Dashboard</title>
 
     <link rel="stylesheet" href="{{ url_for('static', filename='css/dashboard.css') }}">
+    <link rel="stylesheet" href="{{ url_for('static', filename='css/footer.css') }}">
 </head>
 
 <body>
     <nav class="dashboard-nav">
         <a class="brand" href="{{ url_for('main.home') }}">
             <span class="brand-mark">♛</span>
-            <span>8-Damen- und 8-Türme Solver</span>
+            <span data-i18n="navBrand">8-Damen- und 8-Türme Solver</span>
         </a>
 
         <div class="nav-actions">
-            <a class="nav-link" href="{{ url_for('main.dashboard') }}" id="navDashboardLink">Dashboard</a>
+            <a class="nav-link" href="{{ url_for('main.dashboard') }}" id="navDashboardLink"
+                data-i18n="navDashboard">Dashboard</a>
 
             <button class="nav-link-button lang-switch" id="langSwitch" type="button"
                 aria-label="Sprache wechseln">DE</button>
 
             <a class="account-shortcut" href="{{ url_for('login.login_settings') }}"
-                aria-label="Konto und Login-Einstellungen öffnen">
+                data-i18n-aria-label="accountShortcutAria" aria-label="Konto und Login-Einstellungen öffnen">
                 <span class="account-avatar" aria-hidden="true">{{ current_user.username[:1]|upper }}</span>
                 <span class="account-copy">
-                    <span class="account-label" id="accountLabel">Account</span>
+                    <span class="account-label" id="accountLabel" data-i18n="accountLabel">Account</span>
                     <span class="account-name">{{ current_user.username }}</span>
                 </span>
             </a>
 
             <form action="{{ url_for('login.logout') }}" method="post" class="nav-logout-form">
-                <button class="nav-link-button" type="submit">Logout</button>
+                <button class="nav-link-button" type="submit" data-i18n="navLogout">Logout</button>
             </form>
         </div>
     </nav>
@@ -40,7 +42,7 @@
     <button class="settings-trigger" id="settingsTrigger" onclick="toggleSidebar()" type="button"
         aria-controls="settingsSidebar" aria-expanded="false">
         <span class="settings-trigger-arrow" id="settingsTriggerArrow">→</span>
-        <span class="settings-trigger-label" id="settingsTriggerLabel">Brett-Einstellungen</span>
+        <span class="settings-trigger-label" id="settingsTriggerLabel">Spiel-Einstellungen</span>
     </button>
 
     <div class="container">
@@ -55,16 +57,22 @@
         {% endwith %}
 
         <section class="dashboard-intro card">
-            <p class="section-kicker" id="introKicker">Puzzle-Modus</p>
-            <h1 id="introTitle">Wähl deinen Modus und löse das Brett auf deine Art.</h1>
-            <p class="dashboard-intro-text" id="introText">
+            <p class="section-kicker" id="introKicker" data-i18n="introKicker">Puzzle-Modus</p>
+            <h1 id="introTitle" data-i18n="introTitle">Wähl deinen Modus und löse das Brett auf deine Art.</h1>
+            <p class="dashboard-intro-text" id="introText" data-i18n="introText">
                 Wechsle zwischen Damen und Türmen, nutze Animation oder Sofort-Lösung und öffne die
                 Brett-Einstellungen jederzeit über den linken Seiten-Tab.
             </p>
 
-            <div class="mode-switch" aria-label="Spielmodus">
-                <button class="btn active" onclick="setMode('queens')" id="btnQueens" type="button">♛ Damen</button>
-                <button class="btn secondary" onclick="setMode('rooks')" id="btnRooks" type="button">♜ Tuerme</button>
+            <div class="mode-switch" data-i18n-aria-label="modeSwitchAria" aria-label="Spielmodus">
+                <button class="btn secondary" onclick="setMode('rooks')" id="btnRooks" type="button">
+                    <span aria-hidden="true">♜</span>
+                    <span data-i18n="btnRooks">Türme</span>
+                </button>
+                <button class="btn active" onclick="setMode('queens')" id="btnQueens" type="button">
+                    <span aria-hidden="true">♛</span>
+                    <span data-i18n="btnQueens">Damen</span>
+                </button>
             </div>
         </section>
 
@@ -74,12 +82,14 @@
                     <p class="section-kicker" id="gameModeEyebrow">Damen-Modus</p>
                     <h2 id="gameTitle">Damen-Spielbrett</h2>
                     <p class="board-mode-text" id="boardModeText">
-                        Platziere Damen so, dass keine zwei dieselbe Spalte oder Diagonale teilen.
+                        Platziere Damen frei auf dem Brett. Konflikte entstehen in derselben Reihe, Spalte oder
+                        Diagonale.
                     </p>
                 </div>
 
                 <button class="info-button" id="infoButton" onclick="toggleInfoModal(true)" type="button"
-                    aria-label="Spielregeln und Hilfe anzeigen">Regeln & Hilfe</button>
+                    data-i18n="infoButton" data-i18n-aria-label="infoButton"
+                    aria-label="Spielregeln und Hilfe anzeigen">Spielanleitung</button>
             </div>
 
             <p class="board-size-info" id="boardSizeInfo"><span id="boardSizeInfoPrefix">Aktuelle Brettgrösse im
@@ -87,17 +97,17 @@
                 <span id="boardSizeValue">8</span> x <span id="boardSizeValueMirror">8</span>
             </p>
 
-            <div class="game-stats" aria-label="Spielstatus">
+            <div class="game-stats" data-i18n-aria-label="gameStatsAria" aria-label="Spielstatus">
                 <article class="game-stat-card">
-                    <p class="game-stat-label" id="stepsLabel">Schritte</p>
+                    <p class="game-stat-label" id="stepsLabel" data-i18n="stepsLabel">Schritte</p>
                     <p class="game-stat-value" id="stepCounterValue">0</p>
                 </article>
                 <article class="game-stat-card">
-                    <p class="game-stat-label" id="timeLabel">Zeit</p>
+                    <p class="game-stat-label" id="timeLabel" data-i18n="timeLabel">Zeit</p>
                     <p class="game-stat-value" id="timerValue">00:00:00</p>
                 </article>
                 <article class="game-stat-card">
-                    <p class="game-stat-label" id="statusLabel">Status</p>
+                    <p class="game-stat-label" id="statusLabel" data-i18n="statusLabel">Status</p>
                     <p class="game-stat-value game-stat-status" id="gameProgressState">Läuft</p>
                 </article>
             </div>
@@ -109,67 +119,31 @@
                 </p>
             </div>
 
-            <div class="board" id="board"></div>
-
-            <div class="controls">
-                <button class="btn secondary" onclick="resetBoard()" id="btnReset" type="button">Brett
-                    zuruecksetzen</button>
-                <div class="controls-save-row">
-                    <button class="btn" onclick="openSavePanel()" id="btnSave" type="button">Speichern</button>
-                    <button class="btn secondary" onclick="openSavePointsPanel()" id="btnLoad"
-                        type="button">Save-Points</button>
+            <div class="board-stage">
+                <div class="board-shell">
+                    <div id="board"></div>
                 </div>
+
+                <div class="board-navigator" id="boardNavigator" hidden>
+                    <button class="btn secondary board-nav-button" onclick="previousSolverStep()" id="btnPrevStep"
+                        type="button" data-i18n="btnPrevStep">
+                        Zurück
+                    </button>
+                    <p class="solver-step-info" id="solverStepInfo">Schritt 0 / 0</p>
+                    <button class="btn secondary board-nav-button" onclick="nextSolverStep()" id="btnNextStep"
+                        type="button" data-i18n="btnNextStep">
+                        Vorwärts
+                    </button>
+                </div>
+
+                <p class="solver-message solver-message-inline" id="solverMessage">Lade eine Animation und steuere sie
+                    am Brett oder spiele sie automatisch ab.</p>
             </div>
 
-            <div class="solver-panel">
-                <div class="solver-panel-header">
-                    <div>
-                        <p class="section-kicker" id="solverKicker">Solver</p>
-                        <h3 id="solverTitle">Lösungswerkzeuge</h3>
-                        <p class="solver-message" id="solverMessage">Bereite einen Ablauf vor und spiele ihn Schritt
-                            für Schritt ab.</p>
-                    </div>
-                    <p class="solver-step-info" id="solverStepInfo">Schritt 0 / 0</p>
-                </div>
-
-                <div class="solver-groups">
-                    <section class="solver-group">
-                        <h4 id="animationSolverTitle">Animations-Solver</h4>
-                        <p class="solver-group-text" id="animationSolverText">
-                            Bereite den Lösungsweg vor, gehe ihn manüll Schritt für Schritt durch oder spiele die
-                            Animation automatisch ab.
-                        </p>
-
-                        <div class="solver-controls">
-                            <button class="btn" onclick="prepareSolutionTrace()" id="btnPrepareSolve"
-                                type="button">Animation vorbereiten</button>
-                            <button class="btn secondary" onclick="nextSolverStep()" id="btnNextStep"
-                                type="button">Nächster Schritt</button>
-                            <button class="btn secondary" onclick="toggleSolverPlayback()" id="btnPlayPause"
-                                type="button">Animation abspielen</button>
-                        </div>
-
-                        <div class="solver-speed">
-                            <label class="solver-speed-label" id="solverSpeedLabel"
-                                for="solverSpeedInput">Animationsgeschwindigkeit</label>
-                            <input id="solverSpeedInput" type="range" min="80" max="900" step="20" value="320"
-                                oninput="updateSolverSpeed(this.value)">
-                            <span class="solver-speed-value" id="solverSpeedValue">320 ms</span>
-                        </div>
-                    </section>
-
-                    <section class="solver-group instant-solver-group">
-                        <h4 id="instantSolverTitle">Sofort-Lösung</h4>
-                        <p class="solver-group-text" id="instantSolverText">
-                            Lade direkt eine gültige Lösung, ohne Zwischenschritte oder Animation.
-                        </p>
-
-                        <div class="instant-solver-actions">
-                            <button class="btn accent" onclick="instantSolve()" id="btnInstantSolve"
-                                type="button">Sofort lösen</button>
-                        </div>
-                    </section>
-                </div>
+            <div class="controls">
+                <button class="btn secondary" onclick="resetBoard()" id="btnReset" type="button"
+                    data-i18n="btnReset">Brett
+                    zurücksetzen</button>
             </div>
         </div>
 
@@ -184,32 +158,34 @@
         <div class="card">
             <div class="history-header">
                 <div>
-                    <p class="section-kicker" id="historyKicker">Save-Points</p>
-                    <h3 id="historyTitle">Gespeicherte Zeiten und Fortschritte</h3>
-                    <p class="history-subtitle" id="historySubtitle">Die Tabelle zeigt gespeicherte Save-Points mit
+                    <p class="section-kicker" id="historyKicker" data-i18n="historyKicker">Save-Points</p>
+                    <h3 id="historyTitle" data-i18n="historyTitle">Gespeicherte Zeiten und Fortschritte</h3>
+                    <p class="history-subtitle" id="historySubtitle" data-i18n="historySubtitle">Die Tabelle zeigt
+                        gespeicherte Save-Points mit
                         Zeit, Schritten und
                         Status.</p>
                 </div>
-                <button class="btn secondary" onclick="refreshTimeHistory()" id="btnRefreshHistory"
-                    type="button">Aktualisieren</button>
+                <button class="btn secondary" onclick="refreshTimeHistory()" id="btnRefreshHistory" type="button"
+                    data-i18n="btnRefreshHistory">Aktualisieren</button>
             </div>
 
             <div class="history-table-wrapper">
                 <table class="history-table">
                     <thead>
                         <tr>
-                            <th id="historyHeadSave">Save-Point</th>
-                            <th id="historyHeadMode">Modus</th>
-                            <th id="historyHeadBoard">Brett</th>
-                            <th id="historyHeadSteps">Schritte</th>
-                            <th id="historyHeadTime">Zeit</th>
-                            <th id="historyHeadStatus">Status</th>
-                            <th id="historyHeadSaved">Gespeichert</th>
+                            <th id="historyHeadSave" data-i18n="historyHeadSave">Save-Point</th>
+                            <th id="historyHeadMode" data-i18n="historyHeadMode">Modus</th>
+                            <th id="historyHeadBoard" data-i18n="historyHeadBoard">Brett</th>
+                            <th id="historyHeadSteps" data-i18n="historyHeadSteps">Schritte</th>
+                            <th id="historyHeadTime" data-i18n="historyHeadTime">Zeit</th>
+                            <th id="historyHeadStatus" data-i18n="historyHeadStatus">Status</th>
+                            <th id="historyHeadSaved" data-i18n="historyHeadSaved">Gespeichert</th>
                         </tr>
                     </thead>
                     <tbody id="timeHistoryTableBody">
                         <tr>
-                            <td colspan="7" class="history-empty">Noch keine gespeicherten Zeiten vorhanden.</td>
+                            <td colspan="7" class="history-empty" data-i18n="historyEmpty">Noch keine gespeicherten
+                                Zeiten vorhanden.</td>
                         </tr>
                     </tbody>
                 </table>
@@ -217,92 +193,147 @@
         </div>
     </div>
 
+    {% include "partials/footer.html" %}
+
     <aside class="sidebar settings-sidebar" id="settingsSidebar" aria-hidden="true">
         <div class="sidebar-header">
-            <h3 id="settingsSidebarTitle">Brett-Einstellungen</h3>
+            <h3 id="settingsSidebarTitle" data-i18n="settingsSidebarTitle">Spiel-Einstellungen</h3>
             <button class="btn secondary sidebar-close" onclick="toggleSidebar(false)" id="settingsSidebarClose"
-                type="button">Schliessen</button>
+                type="button" data-i18n="settingsSidebarClose">Schliessen</button>
         </div>
 
-        <p id="settingsSidebarText">Passe die Brettgrösse zwischen 4 und 13 an.</p>
+        <section class="settings-section">
+            <p class="section-kicker" id="boardSettingsKicker" data-i18n="boardSettingsKicker">Brett</p>
+            <h4 id="boardSettingsTitle" data-i18n="boardSettingsTitle">Brettgrösse</h4>
+            <p id="settingsSidebarText" data-i18n="settingsSidebarText">Passe die Brettgrösse zwischen 4 und 13 an.</p>
 
-        <label class="sidebar-label" id="boardSizeInputLabel" for="boardSizeInput">Grösse</label>
-        <input id="boardSizeInput" type="range" min="4" max="13" value="8" oninput="previewBoardSize(this.value)">
-        <div class="sidebar-size-row">
-            <strong><span id="sidebarBoardSizeValue">8</span> x <span id="sidebarBoardSizeValueMirror">8</span></strong>
-        </div>
+            <label class="sidebar-label" id="boardSizeInputLabel" for="boardSizeInput"
+                data-i18n="boardSizeInputLabel">Grösse</label>
+            <input id="boardSizeInput" type="range" min="4" max="13" value="8" oninput="previewBoardSize(this.value)">
+            <div class="sidebar-size-row">
+                <strong><span id="sidebarBoardSizeValue">8</span> x <span
+                        id="sidebarBoardSizeValueMirror">8</span></strong>
+            </div>
 
-        <button class="btn" onclick="applyBoardSize()" id="applyBoardSizeButton" type="button">Grösse anwenden</button>
-        <p class="sidebar-hint" id="settingsSidebarHint">Beim Ändern wird das Brett zur Sicherheit zurückgesetzt. Auf
-            dem Handy ist 8x8 eingeplant, grössere Bretter können abgeschnitten wirken.</p>
+            <button class="btn" onclick="applyBoardSize()" id="applyBoardSizeButton" type="button"
+                data-i18n="applyBoardSizeButton">Grösse anwenden</button>
+            <p class="sidebar-hint" id="settingsSidebarHint" data-i18n="settingsSidebarHint">Beim Ändern wird das Brett
+                zur Sicherheit zurückgesetzt. Auf
+                dem Handy ist 8x8 eingeplant, grössere Bretter können abgeschnitten wirken.</p>
+        </section>
+
+        <section class="settings-section">
+            <p class="section-kicker" id="saveSettingsKicker" data-i18n="saveSettingsKicker">Speichern</p>
+            <h4 id="saveSettingsTitle" data-i18n="saveSettingsTitle">Fortschritt speichern</h4>
+            <p id="saveSettingsText" data-i18n="saveSettingsText">Öffne hier die Optionen zum Speichern oder Laden
+                deiner Save-Points.</p>
+
+            <div class="settings-action-grid">
+                <button class="btn" onclick="openSavePanel()" id="btnSave" type="button"
+                    data-i18n="btnSave">Speichern</button>
+                <button class="btn secondary" onclick="openSavePointsPanel()" id="btnLoad" type="button"
+                    data-i18n="btnLoad">Save-Points</button>
+            </div>
+        </section>
+
+        <section class="settings-section">
+            <p class="section-kicker" id="solutionSettingsKicker" data-i18n="solutionSettingsKicker">Lösung</p>
+            <h4 id="solutionSettingsTitle" data-i18n="solutionSettingsTitle">Lösungswerkzeuge</h4>
+            <p id="solutionSettingsText" data-i18n="solutionSettingsText">Lade eine Animation, steuere sie am Brett mit
+                Vorwärts und Zurück oder spiele sie automatisch ab.</p>
+
+            <div class="settings-action-grid">
+                <button class="btn" onclick="prepareSolutionTrace()" id="btnPrepareSolve" type="button"
+                    data-i18n="btnPrepareSolve">Animation laden</button>
+                <button class="btn secondary" onclick="toggleSolverPlayback()" id="btnPlayPause" type="button"
+                    data-i18n="btnPlayPause">Animation abspielen</button>
+                <button class="btn accent" onclick="instantSolve()" id="btnInstantSolve" type="button"
+                    data-i18n="btnInstantSolve">Sofort lösen</button>
+            </div>
+
+            <div class="solver-speed">
+                <label class="solver-speed-label" id="solverSpeedLabel" for="solverSpeedInput"
+                    data-i18n="solverSpeedLabel">Animationsgeschwindigkeit</label>
+                <input id="solverSpeedInput" type="range" min="80" max="900" step="20" value="320"
+                    oninput="updateSolverSpeed(this.value)">
+                <span class="solver-speed-value" id="solverSpeedValue">320 ms</span>
+            </div>
+        </section>
     </aside>
 
     <aside class="sidebar save-sidebar" id="saveSidebar" aria-hidden="true">
         <div class="sidebar-header">
-            <h3 id="saveSidebarTitle">Speicherpunkt</h3>
+            <h3 id="saveSidebarTitle" data-i18n="saveSidebarTitle">Speicherpunkt</h3>
             <button class="btn secondary sidebar-close" onclick="toggleSavePanel(false)" id="saveSidebarClose"
-                type="button">Schliessen</button>
+                type="button" data-i18n="saveSidebarClose">Schliessen</button>
         </div>
 
-        <p id="saveSidebarText">Gib dem Spielstand einen klaren Namen und optional eine kurze Notiz.</p>
+        <p id="saveSidebarText" data-i18n="saveSidebarText">Gib dem Spielstand einen klaren Namen und optional eine
+            kurze Notiz.</p>
 
-        <label class="sidebar-label" id="saveNameLabel" for="saveNameInput">Name</label>
+        <label class="sidebar-label" id="saveNameLabel" for="saveNameInput" data-i18n="saveNameLabel">Name</label>
         <input class="sidebar-input" id="saveNameInput" type="text" maxlength="80"
-            placeholder="z. B. Fast gelöste Dame 8x8">
+            placeholder="z. B. Fast gelöste Dame 8x8" data-i18n-placeholder="saveNamePlaceholder">
 
-        <label class="sidebar-label" id="saveNoteLabel" for="saveNoteInput">Notiz</label>
+        <label class="sidebar-label" id="saveNoteLabel" for="saveNoteInput" data-i18n="saveNoteLabel">Notiz</label>
         <textarea class="sidebar-input sidebar-textarea" id="saveNoteInput" rows="4" maxlength="240"
-            placeholder="z. B. Gute Startposition für Türmetest"></textarea>
+            placeholder="z. B. Gute Startposition für Türmetest" data-i18n-placeholder="saveNotePlaceholder"></textarea>
 
         <label class="sidebar-checkbox">
             <input id="saveFavoriteInput" type="checkbox">
-            <span id="saveFavoriteLabel">Als Favorit markieren</span>
+            <span id="saveFavoriteLabel" data-i18n="saveFavoriteLabel">Als Favorit markieren</span>
         </label>
 
-        <button class="btn" onclick="saveGame()" id="saveNowButton" type="button">Jetzt speichern</button>
+        <button class="btn" onclick="saveGame()" id="saveNowButton" type="button" data-i18n="saveNowButton">Jetzt
+            speichern</button>
     </aside>
 
     <aside class="sidebar save-points-sidebar" id="savePointsSidebar" aria-hidden="true">
         <div class="sidebar-header">
-            <h3 id="savePointsSidebarTitle">Save-Points</h3>
+            <h3 id="savePointsSidebarTitle" data-i18n="savePointsSidebarTitle">Save-Points</h3>
             <button class="btn secondary sidebar-close" onclick="toggleSavePointsPanel(false)"
-                id="savePointsSidebarClose" type="button">Schliessen</button>
+                id="savePointsSidebarClose" type="button" data-i18n="savePointsSidebarClose">Schliessen</button>
         </div>
 
-        <p id="savePointsSidebarText">Wähle einen Speicherstand aus der Liste.</p>
+        <p id="savePointsSidebarText" data-i18n="savePointsSidebarText">Wähle einen Speicherstand aus der Liste.</p>
 
         <div class="save-point-filters">
-            <label class="sidebar-label" id="savePointModeFilterLabel" for="savePointModeFilter">Modus</label>
+            <label class="sidebar-label" id="savePointModeFilterLabel" for="savePointModeFilter"
+                data-i18n="savePointModeFilterLabel">Modus</label>
             <select class="sidebar-input" id="savePointModeFilter" onchange="refreshSavePoints()">
-                <option value="all">Alle</option>
-                <option value="queens">Damen</option>
-                <option value="rooks">Türme</option>
+                <option value="all" data-i18n="filterAll">Alle</option>
+                <option value="queens" data-i18n="filterQueens">Damen</option>
+                <option value="rooks" data-i18n="filterRooks">Türme</option>
             </select>
 
-            <label class="sidebar-label" id="savePointSizeFilterLabel" for="savePointSizeFilter">Brettgrösse</label>
+            <label class="sidebar-label" id="savePointSizeFilterLabel" for="savePointSizeFilter"
+                data-i18n="savePointSizeFilterLabel">Brettgrösse</label>
             <select class="sidebar-input" id="savePointSizeFilter" onchange="refreshSavePoints()">
-                <option value="all">Alle</option>
+                <option value="all" data-i18n="filterAll">Alle</option>
                 {% for board_size in range(4, 14) %}
                 <option value="{{ board_size }}">{{ board_size }} x {{ board_size }}</option>
                 {% endfor %}
             </select>
 
-            <label class="sidebar-label" id="savePointSortFilterLabel" for="savePointSortFilter">Sortierung</label>
+            <label class="sidebar-label" id="savePointSortFilterLabel" for="savePointSortFilter"
+                data-i18n="savePointSortFilterLabel">Sortierung</label>
             <select class="sidebar-input" id="savePointSortFilter" onchange="refreshSavePoints()">
-                <option value="newest">Neueste zuerst</option>
-                <option value="oldest">älteste zuerst</option>
-                <option value="updated">Zuletzt bearbeitet</option>
-                <option value="favorites">Favoriten zuerst</option>
+                <option value="newest" data-i18n="filterNewest">Neueste zuerst</option>
+                <option value="oldest" data-i18n="filterOldest">älteste zuerst</option>
+                <option value="updated" data-i18n="filterUpdated">Zuletzt bearbeitet</option>
+                <option value="favorites" data-i18n="filterFavorites">Favoriten zuerst</option>
             </select>
 
             <label class="sidebar-checkbox">
                 <input id="savePointFavoritesOnly" type="checkbox" onchange="refreshSavePoints()">
-                <span id="savePointFavoritesOnlyLabel">Nur Favoriten anzeigen</span>
+                <span id="savePointFavoritesOnlyLabel" data-i18n="savePointFavoritesOnlyLabel">Nur Favoriten
+                    anzeigen</span>
             </label>
         </div>
 
         <div class="save-points-list" id="savePointsList">
-            <p class="sidebar-hint" id="savePointsEmptyState">Noch keine Speicherstände gefunden.</p>
+            <p class="sidebar-hint" id="savePointsEmptyState" data-i18n="savePointsEmptyState">Noch keine Speicherstände
+                gefunden.</p>
         </div>
     </aside>
 
@@ -313,31 +344,38 @@
     <div class="modal-backdrop" id="infoModalBackdrop" onclick="toggleInfoModal(false)"></div>
     <section class="modal" id="infoModal" aria-hidden="true" aria-labelledby="infoModalTitle">
         <div class="modal-header">
-            <h3 id="infoModalTitle">Spielregeln und Acht-Damen-Problem</h3>
-            <button class="btn secondary sidebar-close" onclick="toggleInfoModal(false)"
-                type="button">Schliessen</button>
+            <h3 id="infoModalTitle">Spielanleitung</h3>
+            <button class="btn secondary sidebar-close" onclick="toggleInfoModal(false)" type="button"
+                data-i18n="infoModalClose">Schliessen</button>
         </div>
 
         <div class="modal-content">
-            <p>Setze pro Reihe genau eine Figur auf das Brett. Eine gültige Lösung hat keine Konflikte.</p>
+            <p data-i18n="infoModalIntro">Das Schachbrett besteht aus vielen quadratischen Feldern. Jedes Feld kann
+                leer sein oder genau eine Figur enthalten. Deine Aufgabe ist es, Figuren auf das Brett zu setzen,
+                ohne dass sie sich gegenseitig angreifen. Das Puzzle ist erst gelöst, wenn genau so viele Figuren auf
+                dem Brett stehen wie das Brett Felder pro Seite hat, also zum Beispiel 8 Figuren auf einem
+                8x8-Brett.</p>
 
-            <h4>So funktioniert der aktuelle Modus</h4>
-            <p id="infoModeRuleText">Im Damen-Modus dürfen sich Damen weder in derselben Spalte noch diagonal
-                angreifen. Mit einem Klick setzt oder entfernst du eine Figur.</p>
+            <h4 data-i18n="infoModalModeHeading">Grundregeln</h4>
+            <p id="infoModeRuleText">In diesem Modus spielst du mit Damen. Eine Dame ist die Figur mit dem Symbol ♛.
+                Sie darf keine andere Dame in derselben waagerechten Reihe, senkrechten Spalte oder schrägen
+                Diagonale treffen. Mit einem Klick setzt du eine Dame auf ein freies Feld oder entfernst sie wieder.</p>
 
-            <h4 id="infoModalProblemHeading">Was ist das Acht-Damen-Problem?</h4>
-            <p id="infoModalProblemText">Das klassische Acht-Damen-Problem fragt nach einer Anordnung von acht Damen
-                auf einem 8x8-Brett, bei der sich keine zwei Damen schlagen. Es ist ein bekanntes Beispiel für
-                kombinatorische Suche und Backtracking.</p>
+            <h4 id="infoModalProblemHeading">Was ist eine Dame?</h4>
+            <p id="infoModalProblemText">Eine Dame ist eine Schachfigur. In diesem Spiel musst du keine Schachregeln
+                lernen, sondern nur wissen: Eine Dame kann gerade und schräg über das Brett wirken. Darum müssen
+                Damen genug Abstand haben, damit sie sich nicht gegenseitig erreichen.</p>
 
-            <h4>Was zeigen Zeit und Schritte?</h4>
-            <p>Der Schrittzähler erfasst deine Züge auf dem Brett. Die Zeit läuft für das aktuelle Spiel weiter,
+            <h4 data-i18n="infoModalTimeHeading">Was zeigen Zeit und Schritte?</h4>
+            <p data-i18n="infoModalTimeText">Der Schrittzähler erfasst deine Züge auf dem Brett. Die Zeit läuft für das
+                aktuelle Spiel weiter,
                 auch wenn du die Seite neu lädst. Beim Speichern werden Zeit und Schritte zusammen mit dem
                 Save-Point abgelegt.</p>
         </div>
     </section>
 
-    <script src="{{ url_for('static', filename='js/dashboard.js') }}"></script>
+    <script src="{{ url_for('static', filename='js/language.js') }}" defer></script>
+    <script src="{{ url_for('static', filename='js/dashboard.js') }}" defer></script>
 </body>
 
-</html>
+</html>

app/templates/impressum.html

@@ -0,0 +1,83 @@
+<!DOCTYPE html>
+<html lang="de">
+
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title data-i18n="pageTitle">Impressum</title>
+    <link rel="stylesheet" href="{{ url_for('static', filename='css/legal.css') }}">
+    <link rel="stylesheet" href="{{ url_for('static', filename='css/footer.css') }}">
+</head>
+
+<body data-legal-page="imprint">
+    <header class="legal-header">
+        <nav class="legal-nav">
+            <a class="brand" href="{{ url_for('main.home') }}">
+                <span class="brand-mark">♛</span>
+                <span data-i18n="navBrand">8-Damen- und 8-Türme Solver</span>
+            </a>
+
+            <div class="legal-nav-links">
+                <button class="lang-switch" id="langSwitch" type="button" aria-label="Sprache wechseln">DE</button>
+                <a href="{{ url_for('main.home') }}" data-i18n="navHome">Startseite</a>
+                {% if current_user.is_authenticated %}
+                <a href="{{ url_for('main.dashboard') }}" data-i18n="navDashboard">Dashboard</a>
+                {% else %}
+                <a href="{{ url_for('login.login') }}" data-i18n="navLogin">Login</a>
+                {% endif %}
+            </div>
+        </nav>
+    </header>
+
+    <main class="legal-main">
+        <section class="legal-hero">
+            <p class="legal-eyebrow" data-i18n="heroEyebrow">Rechtliche Hinweise</p>
+            <h1 data-i18n="heroTitle">Impressum</h1>
+        </section>
+
+        <section class="legal-card">
+            <h2 data-i18n="contactTitle">Kontakt</h2>
+            <p>
+                <strong data-i18n="contactName">Jérôme Bachmann</strong><br>
+                <span data-i18n="contactEmailLabel">E-Mail:</span> jerome.bachmann@bachmannj.ch<br>
+            </p>
+        </section>
+
+        <section class="legal-card">
+            <h2 data-i18n="projectResponsibilityTitle">Projektverantwortung</h2>
+            <p data-i18n="projectResponsibilityText">
+                Dieses Webprojekt wurde im Rahmen eines Schulprojekts zum Acht-Damen- und Acht-Türme-Problem
+                erstellt. Inhaltlich verantwortlich ist die jeweils oben genannte verantwortliche Stelle.
+            </p>
+        </section>
+
+        <section class="legal-card">
+            <h2 data-i18n="contentLiabilityTitle">Haftung für Inhalte</h2>
+            <p data-i18n="contentLiabilityText">
+                Die Inhalte dieser Website wurden mit Sorgfalt erstellt. Für die Richtigkeit, Vollständigkeit und
+                Aktualität der Inhalte kann jedoch keine Gewähr übernommen werden. Bei Bekanntwerden von
+                Rechtsverletzungen werden entsprechende Inhalte umgehend überarbeitet oder entfernt.
+            </p>
+        </section>
+
+        <section class="legal-card">
+            <h2 data-i18n="linksLiabilityTitle">Haftung fuer Links</h2>
+            <p data-i18n="linksLiabilityText">
+                Diese Website kann Links zu externen Angeboten enthalten. Fuer deren Inhalte sind ausschliesslich die
+                jeweiligen Betreiber verantwortlich. Eine permanente inhaltliche Kontrolle verlinkter Seiten ist ohne
+                konkrete Anhaltspunkte einer Rechtsverletzung nicht zumutbar.
+            </p>
+        </section>
+
+        <section class="legal-card">
+            <h2 data-i18n="versionTitle">Stand</h2>
+            <p data-i18n="versionText">Stand dieser Vorlage: April 2026</p>
+        </section>
+    </main>
+
+    {% include "partials/footer.html" %}
+    <script src="{{ url_for('static', filename='js/language.js') }}" defer></script>
+    <script src="{{ url_for('static', filename='js/legal.js') }}" defer></script>
+</body>
+
+</html>

app/templates/index.html

@@ -4,24 +4,25 @@
 <head>
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
-    <title data-i18n="meta.title">8-Damen- und 8-Tuerme Solver</title>
+    <title data-i18n="meta.title">8-Damen- und 8-Türme Solver</title>
     <link rel="stylesheet" href="{{ url_for('static', filename='css/index.css') }}">
+    <link rel="stylesheet" href="{{ url_for('static', filename='css/footer.css') }}">
 </head>
 
 <body>
     <header class="landing-nav">
         <a class="brand" href="{{ url_for('main.home') }}">
             <span class="brand-mark">♛</span>
-            <span data-i18n="nav.brand">8-Damen- und 8-Tuerme Solver</span>
+            <span data-i18n="nav.brand">8-Damen- und 8-Türme Solver</span>
         </a>
 
         <nav class="landing-links">
             <a href="#problem" data-i18n="nav.problem">Problem</a>
-            <a href="#features" data-i18n="nav.features">Features</a>
+            <a href="#features" data-i18n="nav.features">Funktionen</a>
             <a href="#journey" data-i18n="nav.journey">Ablauf</a>
             <button class="lang-switch" id="langSwitch" type="button" aria-label="Sprache wechseln">DE</button>
-            <a class="nav-cta secondary" href="{{ url_for('login.login') }}" data-i18n="nav.login">Login</a>
-            <a class="nav-cta" href="{{ url_for('login.register') }}" data-i18n="nav.signup">Create Account</a>
+            <a class="nav-cta secondary" href="{{ url_for('login.login') }}" data-i18n="nav.login">Anmelden</a>
+            <a class="nav-cta" href="{{ url_for('login.register') }}" data-i18n="nav.signup">Account erstellen</a>
         </nav>
     </header>
 
@@ -32,42 +33,28 @@
                 </p>
                 <h1 data-i18n="hero.title">Entdecke das Acht-Damen- und Acht-Türme-Problem.</h1>
                 <p class="hero-text" data-i18n="hero.text">
-                    Diese App macht aus einem klassischen Informatik- und Mathematikproblem ein interaktives Erlebnis:
+                    Diese Webanwendung macht aus einem klassischen Informatik- und Mathematikproblem ein interaktives
+                    Erlebnis:
                     Setze Damen oder Türme, verfolge den Solver Schritt für Schritt, miss deine Zeit und speichere
-                    clevere Zwischenstände.
+                    Zwischenstände.
                 </p>
 
                 <div class="hero-actions">
                     <a class="hero-button primary" href="{{ url_for('login.register') }}"
                         data-i18n="hero.primaryCta">Jetzt starten</a>
                     <a class="hero-button secondary" href="{{ url_for('login.login') }}"
-                        data-i18n="hero.secondaryCta">Bereits Account? Login</a>
-                </div>
-
-                <div class="hero-facts">
-                    <article>
-                        <strong data-i18n="hero.fact1Title">Skalierbar</strong>
-                        <span data-i18n="hero.fact1Text">Brettgrösse flexibel anpassen</span>
-                    </article>
-                    <article>
-                        <strong data-i18n="hero.fact2Title">Schritt für Schritt</strong>
-                        <span data-i18n="hero.fact2Text">Solver mit Animation</span>
-                    </article>
-                    <article>
-                        <strong data-i18n="hero.fact3Title">Save-Points</strong>
-                        <span data-i18n="hero.fact3Text">Zeit und Fortschritt behalten</span>
-                    </article>
+                        data-i18n="hero.secondaryCta">Bereits ein Account? Anmelden</a>
                 </div>
             </div>
 
             <div class="hero-visual">
                 <div class="board-showcase" id="heroBoard" aria-hidden="true"></div>
                 <div class="floating-card solver-card">
-                    <p class="floating-label" data-i18n="hero.solverLabel">Solver</p>
-                    <p class="floating-value" data-i18n="hero.solverValue">Backtracking live</p>
+                    <p class="floating-label" data-i18n="hero.solverLabel">Lösungshelfer</p>
+                    <p class="floating-value" data-i18n="hero.solverValue">Backtracking in Echtzeit</p>
                 </div>
                 <div class="floating-card timer-card">
-                    <p class="floating-label" data-i18n="hero.challengeLabel">Challenge</p>
+                    <p class="floating-label" data-i18n="hero.challengeLabel">Herausforderung</p>
                     <p class="floating-value" data-i18n="hero.challengeValue">Zeit und Schritte messen</p>
                 </div>
             </div>
@@ -75,17 +62,21 @@
 
         <section class="info-band" id="problem">
             <div class="info-band-inner">
-                <p class="eyebrow" data-i18n="problem.eyebrow">Warum dieses Problem spannend ist</p>
-                <h2 data-i18n="problem.title">Die Acht-Damen- und Acht-Tuerme-Probleme sind mehr als Schachrätsel.</h2>
+                <p class="eyebrow" data-i18n="problem.eyebrow">Was ist das Acht-Damen-Problem?</p>
+                <h2 data-i18n="problem.title">Eine klassische schachmathematische Aufgabe mit überraschend vielen
+                    Lösungen.</h2>
                 <p data-i18n="problem.text">
-                    Beim Acht-Damen-Problem suchst du eine Anordnung von acht Damen auf einem Schachbrett, sodass sich
-                    keine zwei Damen schlagen. Beim Acht-Türme-Problem gilt dieselbe Idee für Türme, nur mit
-                    einfacheren Konfliktregeln. Beide Aufgaben zeigen, wie Mustererkennung, systematische Suche und
-                    Backtracking funktionieren.
+                    Das Acht-Damen-Problem ist eine schachmathematische Aufgabe: Acht Damen sollen auf einem
+                    Schachbrett so aufgestellt werden, dass keine zwei Damen dieselbe Reihe, Spalte oder Diagonale
+                    teilen. Das Problem lässt sich auf beliebige Brettgrössen verallgemeinern, indem n Damen auf einem
+                    n x n-Brett platziert werden.
                     <br><br>
-                    Gerade beim Damenproblem wird schnell sichtbar, warum Strategie wichtig ist: Es gibt unzählige
-                    mögliche Platzierungen, aber nur sehr wenige wirklich gültige Lösungen. Genau das macht diese
-                    App spannend, weil man nicht nur das Ergebnis sieht, sondern auch den Weg dorthin.
+                    Für das klassische 8x8-Brett gibt es 92 Lösungen. Zählt man Stellungen, die nur durch Spiegelung
+                    oder Drehung entstehen, als gleich, bleiben 12 eindeutige Lösungen übrig.
+                    <br><br>
+                    <a href="https://de-academic.com/dic.nsf/dewiki/13248" target="_blank"
+                        rel="noopener noreferrer">Quelle:
+                        de-academic.com</a>
                 </p>
             </div>
         </section>
@@ -100,7 +91,7 @@
                 <article class="feature-card">
                     <span class="feature-icon">♟</span>
                     <h3 data-i18n="features.card1Title">Interaktives Brett</h3>
-                    <p data-i18n="features.card1Text">Setze Damen oder Tuerme direkt auf dem Brett und prüfe, ob deine
+                    <p data-i18n="features.card1Text">Setze Damen oder Türme direkt auf dem Brett und prüfe, ob deine
                         Anordnung konfliktfrei ist.</p>
                 </article>
 
@@ -108,7 +99,8 @@
                     <span class="feature-icon">⚙</span>
                     <h3 data-i18n="features.card2Title">Solver mit Animation</h3>
                     <p data-i18n="features.card2Text">Beobachte den Lösungsweg Schritt für Schritt und verstehe, wie
-                        Backtracking arbeitet.</p>
+                        Backtracking arbeitet.
+                    </p>
                 </article>
 
                 <article class="feature-card">
@@ -120,8 +112,8 @@
 
                 <article class="feature-card">
                     <span class="feature-icon">💾</span>
-                    <h3 data-i18n="features.card4Title">Save-Points</h3>
-                    <p data-i18n="features.card4Text">Speichere Zwischenstaende mit Notizen, Zeiten und Schrittzahl für
+                    <h3 data-i18n="features.card4Title">Speicherstände</h3>
+                    <p data-i18n="features.card4Text">Speichere Zwischenstände mit Notizen, Zeiten und Schrittzahl für
                         späteres Weiterarbeiten.</p>
                 </article>
 
@@ -144,8 +136,8 @@
                 <article class="journey-step">
                     <span class="step-number">01</span>
                     <h3 data-i18n="journey.step1Title">Account erstellen</h3>
-                    <p data-i18n="journey.step1Text">Registriere dich und erhalte Zugang zu Dashboard, Save-Points und
-                        deinem Fortschritt.</p>
+                    <p data-i18n="journey.step1Text">Registriere dich und erhalte Zugang zum Dashboard, zu
+                        Speicherständen und zu deinem Fortschritt.</p>
                 </article>
 
                 <article class="journey-step">
@@ -159,8 +151,7 @@
                     <span class="step-number">03</span>
                     <h3 data-i18n="journey.step3Title">Lösen oder analysieren</h3>
                     <p data-i18n="journey.step3Text">Teste eigene Ideen oder lass dir die Lösung visuell vom Solver
-                        lösen lassen, dabei wird 1:1
-                        gezeigt wie der Solver vorgeht.</p>
+                        zeigen, damit du den Lösungsweg besser nachvollziehen kannst.</p>
                 </article>
             </div>
         </section>
@@ -176,18 +167,21 @@
 
                 <div class="hero-actions">
                     <a class="hero-button primary" href="{{ url_for('login.register') }}"
-                        data-i18n="cta.primaryCta">Create Account</a>
+                        data-i18n="cta.primaryCta">Account erstellen</a>
                     <a class="hero-button secondary" href="{{ url_for('login.login') }}"
-                        data-i18n="cta.secondaryCta">Login</a>
+                        data-i18n="cta.secondaryCta">Anmelden</a>
                 </div>
             </div>
         </section>
     </main>
 
+    {% include "partials/footer.html" %}
+
     <script>
         window.LANDING_INITIAL_LANGUAGE = "{{ initial_language }}";
     </script>
-    <script src="{{ url_for('static', filename='js/index.js') }}"></script>
+    <script src="{{ url_for('static', filename='js/language.js') }}" defer></script>
+    <script src="{{ url_for('static', filename='js/index.js') }}" defer></script>
 </body>
 
 </html>

app/templates/login.html

@@ -6,25 +6,27 @@
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <title>Login</title>
     <link rel="stylesheet" href="{{ url_for('static', filename='css/login.css') }}">
+    <link rel="stylesheet" href="{{ url_for('static', filename='css/footer.css') }}">
 </head>
 
 <body>
     <nav class="auth-nav">
         <a class="brand" href="{{ url_for('main.home') }}">
             <span class="brand-mark">♛</span>
-            <span>8-Damen- und 8-Tuerme Solver</span>
+            <span class="nav-brand" data-i18n="navBrand">8-Damen- und 8-Türme Solver</span>
         </a>
 
         <ul class="nav-links">
-            <li><a href="{{ url_for('login.login') }}">Login</a></li>
-            <li><a href="{{ url_for('login.register') }}">Create account</a></li>
+            <li><a href="{{ url_for('login.login') }}" data-i18n="navLogin">Login</a></li>
+            <li><a href="{{ url_for('login.register') }}" data-i18n="navRegister">Create account</a></li>
         </ul>
     </nav>
 
     <main class="auth-shell">
         <section class="auth-panel">
             <h1>Login to your account</h1>
-            <p class="muted">If two-factor authentication is enabled, enter the current 6-digit code from your authenticator app after the password check.</p>
+            <p class="muted">If two-factor authentication is enabled, enter the current 6-digit code from your
+                authenticator app after the password check.</p>
 
             {% with messages = get_flashed_messages(with_categories=true) %}
             {% if messages %}
@@ -50,6 +52,9 @@
         </section>
     </main>
 
+    {% include "partials/footer.html" %}
+
+    <script src="{{ url_for('static', filename='js/language.js') }}" defer></script>
     <script src="{{ url_for('static', filename='js/login.js') }}" defer></script>
 </body>
 

app/templates/login_settings.html

@@ -4,8 +4,9 @@
 <head>
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
-    <title>Login Settings</title>
+    <title data-i18n="pageTitle">Login Settings</title>
     <link rel="stylesheet" href="{{ url_for('static', filename='css/login.css') }}">
+    <link rel="stylesheet" href="{{ url_for('static', filename='css/footer.css') }}">
     <script src="https://cdnjs.cloudflare.com/ajax/libs/qrcodejs/1.0.0/qrcode.min.js" defer></script>
 </head>
 
@@ -13,22 +14,33 @@
     <nav class="auth-nav">
         <a class="brand" href="{{ url_for('main.home') }}">
             <span class="brand-mark">♛</span>
-            <span>8-Damen- und 8-Tuerme Solver</span>
+            <span data-i18n="navBrand">8-Damen- und 8-Türme Solver</span>
         </a>
 
         <ul class="nav-links">
-            <li><a href="{{ url_for('main.dashboard') }}">Dashboard</a></li>
-            <li><a href="{{ url_for('login.login_settings') }}">Login settings</a></li>
+            <li><a href="{{ url_for('main.dashboard') }}" data-i18n="navDashboard">Dashboard</a></li>
+            <li><a href="{{ url_for('login.login_settings') }}" data-i18n="navSettings">Login settings</a></li>
         </ul>
         <form action="{{ url_for('login.logout') }}" method="post" class="nav-form">
-            <button type="submit" class="nav-button">Logout</button>
+            <button type="submit" class="nav-button" id="logoutButton" data-i18n="navLogout">Logout</button>
         </form>
     </nav>
 
     <main class="auth-shell settings-shell">
         <section class="auth-panel settings-panel">
-            <h1>Login settings</h1>
-            <p class="muted">Manage authenticator app 2FA and your password without changing the registration flow.</p>
+            <div class="settings-topbar">
+                <a class="back-link" href="{{ url_for('main.dashboard') }}" data-i18n-aria-label="backToDashboardAria"
+                    aria-label="Back to dashboard">
+                    <span class="back-link-arrow" aria-hidden="true">&larr;</span>
+                    <span data-i18n="backToDashboard">Back to dashboard</span>
+                </a>
+
+                <button class="nav-button lang-switch" id="langSwitch" type="button" aria-label="Switch language">DE</button>
+            </div>
+
+            <h1 data-i18n="settingsTitle">Login settings</h1>
+            <p class="muted" data-i18n="settingsSubtitle">Manage authenticator app 2FA and your password without
+                changing the registration flow.</p>
 
             {% with messages = get_flashed_messages(with_categories=true) %}
             {% if messages %}
@@ -47,81 +59,103 @@
                 <form action="{{ url_for('login.login_settings') }}" method="post">
                     <input type="hidden" name="action" value="disable_two_factor">
 
-                    <h2>Authenticator app 2FA</h2>
-                    <p class="field-hint">2FA is currently enabled for this account.</p>
-                    <p class="field-hint">Use Google Authenticator, Microsoft Authenticator, Authy, or another TOTP app to generate your 6-digit login codes.</p>
+                    <h2 data-i18n="twoFactorTitle">Authenticator app 2FA</h2>
+                    <p class="field-hint" data-i18n="twoFactorEnabledHint">2FA is currently enabled for this account.</p>
+                    <p class="field-hint" data-i18n="twoFactorEnabledAppHint">Use Google Authenticator, Microsoft
+                        Authenticator, Authy, or another TOTP app
+                        to generate your 6-digit login codes.</p>
 
-                    <button class="secondary-button" type="submit" data-loading-label="Disabling 2FA...">Disable 2FA</button>
+                    <button class="secondary-button" type="submit" data-loading-label="Disabling 2FA..."
+                        data-i18n="disableTwoFactorButton" data-i18n-loading-label="disableTwoFactorLoading">Disable
+                        2FA</button>
                 </form>
                 {% elif pending_two_factor_secret %}
                 <form action="{{ url_for('login.login_settings') }}" method="post">
                     <input type="hidden" name="action" value="confirm_two_factor_setup">
 
-                    <h2>Finish 2FA setup</h2>
-                    <p class="field-hint">Scan this QR code with your authenticator app, then enter the current 6-digit code to confirm.</p>
+                    <h2 data-i18n="finishSetupTitle">Finish 2FA setup</h2>
+                    <p class="field-hint" data-i18n="finishSetupHint">Scan this QR code with your authenticator app,
+                        then enter the current 6-digit
+                        code to confirm.</p>
 
                     <div class="qr-panel">
                         <div class="qr-code" data-qr-value="{{ pending_two_factor_uri }}"></div>
                     </div>
-                    <p class="field-hint">If scanning does not work, you can still use the manual setup key below.</p>
+                    <p class="field-hint" data-i18n="scanFallbackHint">If scanning does not work, you can still use the
+                        manual setup key below.</p>
 
-                    <label for="two_factor_secret">Manual setup key</label>
+                    <label for="two_factor_secret" data-i18n="manualSetupKey">Manual setup key</label>
                     <input id="two_factor_secret" type="text" value="{{ pending_two_factor_secret }}" readonly>
 
-                    <label for="two_factor_uri">Setup URI</label>
+                    <label for="two_factor_uri" data-i18n="setupUriLabel">Setup URI</label>
                     <input id="two_factor_uri" type="text" value="{{ pending_two_factor_uri }}" readonly>
-                    <p class="field-hint">This URI is used to generate the QR setup and can be copied as a fallback for compatible apps.</p>
+                    <p class="field-hint" data-i18n="setupUriHint">This URI is used to generate the QR setup and can be
+                        copied as a fallback for
+                        compatible apps.</p>
 
-                    <label for="code">Authenticator code</label>
-                    <input id="code" type="text" name="code" inputmode="numeric" pattern="[0-9]{6}" maxlength="6" required>
+                    <label for="code" data-i18n="authenticatorCodeLabel">Authenticator code</label>
+                    <input id="code" type="text" name="code" inputmode="numeric" pattern="[0-9]{6}" maxlength="6"
+                        required>
 
                     <div class="button-row">
-                        <button class="magnetic" type="submit" data-loading-label="Enabling 2FA...">Confirm and enable</button>
+                        <button class="magnetic" type="submit" data-loading-label="Enabling 2FA..."
+                            data-i18n="confirmAndEnableButton" data-i18n-loading-label="confirmAndEnableLoading">Confirm and
+                            enable</button>
                     </div>
                 </form>
 
                 <form action="{{ url_for('login.login_settings') }}" method="post">
                     <input type="hidden" name="action" value="cancel_two_factor_setup">
 
-                    <h2>Cancel setup</h2>
-                    <p class="field-hint">Cancel the current authenticator setup if you want to restart with a new secret.</p>
+                    <h2 data-i18n="cancelSetupTitle">Cancel setup</h2>
+                    <p class="field-hint" data-i18n="cancelSetupHint">Cancel the current authenticator setup if you want
+                        to restart with a new
+                        secret.</p>
 
-                    <button class="secondary-button" type="submit">Cancel setup</button>
+                    <button class="secondary-button" type="submit" data-i18n="cancelSetupButton">Cancel setup</button>
                 </form>
                 {% else %}
                 <form action="{{ url_for('login.login_settings') }}" method="post">
                     <input type="hidden" name="action" value="start_two_factor_setup">
 
-                    <h2>Authenticator app 2FA</h2>
-                    <p class="field-hint">Protect your account with 6-digit codes from an authenticator app.</p>
-                    <p class="field-hint">After starting setup, you will get a QR code to scan and then confirm once with a live code.</p>
+                    <h2 data-i18n="twoFactorTitle">Authenticator app 2FA</h2>
+                    <p class="field-hint" data-i18n="startSetupHint">Protect your account with 6-digit codes from an
+                        authenticator app.</p>
+                    <p class="field-hint" data-i18n="startSetupHintFollowup">After starting setup, you will get a QR code to scan and then confirm once
+                        with a live code.</p>
 
-                    <button class="magnetic" type="submit" data-loading-label="Starting setup...">Start setup</button>
+                    <button class="magnetic" type="submit" data-loading-label="Starting setup..."
+                        data-i18n="startSetupButton" data-i18n-loading-label="startSetupLoading">Start setup</button>
                 </form>
                 {% endif %}
 
                 <form action="{{ url_for('login.login_settings') }}" method="post">
                     <input type="hidden" name="action" value="password">
 
-                    <h2>Change password</h2>
+                    <h2 data-i18n="changePasswordTitle">Change password</h2>
 
-                    <label for="current_password">Current password</label>
+                    <label for="current_password" data-i18n="currentPasswordLabel">Current password</label>
                     <input id="current_password" type="password" name="current_password" minlength="8" maxlength="128"
                         required>
 
-                    <label for="new_password">New password</label>
+                    <label for="new_password" data-i18n="newPasswordLabel">New password</label>
                     <input id="new_password" type="password" name="new_password" minlength="8" maxlength="128" required>
 
-                    <label for="confirm_password">Confirm new password</label>
+                    <label for="confirm_password" data-i18n="confirmPasswordLabel">Confirm new password</label>
                     <input id="confirm_password" type="password" name="confirm_password" minlength="8" maxlength="128"
                         required>
 
-                    <button class="magnetic" type="submit" data-loading-label="Updating password...">Update password</button>
+                    <button class="magnetic" type="submit" data-loading-label="Updating password..."
+                        data-i18n="updatePasswordButton" data-i18n-loading-label="updatePasswordLoading">Update
+                        password</button>
                 </form>
             </div>
         </section>
     </main>
 
+    {% include "partials/footer.html" %}
+
+    <script src="{{ url_for('static', filename='js/language.js') }}" defer></script>
     <script src="{{ url_for('static', filename='js/login.js') }}" defer></script>
 </body>
 

app/templates/partials/footer.html

@@ -0,0 +1,12 @@
+<footer class="page-footer">
+    <div class="page-footer-inner">
+        <div class="page-footer-copy">
+            <p class="page-footer-text" data-i18n="footerText">Schulprojekt rund um das Acht-Damen- und Acht-Türme-Problem.</p>
+        </div>
+
+        <nav class="page-footer-links" data-i18n-aria-label="footerNavAria" aria-label="Rechtliche Hinweise">
+            <a href="{{ url_for('main.privacy_policy') }}" data-i18n="footerPrivacy">Datenschutzerklärung</a>
+            <a href="{{ url_for('main.imprint') }}" data-i18n="footerImprint">Impressum</a>
+        </nav>
+    </div>
+</footer>

app/templates/privacy.html

@@ -0,0 +1,133 @@
+<!DOCTYPE html>
+<html lang="de">
+
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title data-i18n="pageTitle">Datenschutzerklärung</title>
+    <link rel="stylesheet" href="{{ url_for('static', filename='css/legal.css') }}">
+    <link rel="stylesheet" href="{{ url_for('static', filename='css/footer.css') }}">
+</head>
+
+<body data-legal-page="privacy">
+    <header class="legal-header">
+        <nav class="legal-nav">
+            <a class="brand" href="{{ url_for('main.home') }}">
+                <span class="brand-mark">♛</span>
+                <span data-i18n="navBrand">8-Damen- und 8-Türme Solver</span>
+            </a>
+
+            <div class="legal-nav-links">
+                <button class="lang-switch" id="langSwitch" type="button" aria-label="Sprache wechseln">DE</button>
+                <a href="{{ url_for('main.home') }}" data-i18n="navHome">Startseite</a>
+                {% if current_user.is_authenticated %}
+                <a href="{{ url_for('main.dashboard') }}" data-i18n="navDashboard">Dashboard</a>
+                {% else %}
+                <a href="{{ url_for('login.login') }}" data-i18n="navLogin">Login</a>
+                {% endif %}
+            </div>
+        </nav>
+    </header>
+
+    <main class="legal-main">
+        <section class="legal-hero">
+            <p class="legal-eyebrow" data-i18n="heroEyebrow">Rechtliche Hinweise</p>
+            <h1 data-i18n="heroTitle">Datenschutzerklärung</h1>
+            <p class="legal-lead" data-i18n="heroLead">
+                Diese Seite beschreibt, welche personenbezogenen Daten im Rahmen dieses Schulprojekts verarbeitet
+                werden.
+            </p>
+        </section>
+
+        <section class="legal-card">
+            <h2 data-i18n="dataProcessedTitle">1. Welche Daten verarbeitet werden</h2>
+            <p data-i18n="dataProcessedText">Im Rahmen der Nutzung dieser Webanwendung können insbesondere folgende
+                Daten verarbeitet werden:</p>
+            <ul class="legal-list">
+                <li data-i18n="dataProcessedItem1">Benutzername und verschlüsseltes Passwort bei der Registrierung und
+                    beim Login</li>
+                <li data-i18n="dataProcessedItem2">Daten zur Zwei-Faktor-Authentifizierung, falls diese freiwillig
+                    aktiviert wird</li>
+                <li data-i18n="dataProcessedItem3">gespeicherte Spielstände, Notizen, Schrittzahlen, Zeiten und
+                    Favoriten</li>
+                <li data-i18n="dataProcessedItem4">technische Verbindungsdaten, die durch den Server oder das Hosting
+                    entstehen koennen</li>
+            </ul>
+        </section>
+
+        <section class="legal-card">
+            <h2 data-i18n="processingPurposeTitle">2. Zweck der Verarbeitung</h2>
+            <p data-i18n="processingPurposeText">Die Verarbeitung erfolgt, um die Funktionen dieser Anwendung
+                bereitzustellen. Dazu gehoeren insbesondere:
+            </p>
+            <ul class="legal-list">
+                <li data-i18n="processingPurposeItem1">Erstellung und Verwaltung von Benutzerkonten</li>
+                <li data-i18n="processingPurposeItem2">sicherer Login in das persönliche Dashboard</li>
+                <li data-i18n="processingPurposeItem3">optionale Absicherung des Kontos per Authenticator-App</li>
+                <li data-i18n="processingPurposeItem4">Speichern und Laden von Spielständen</li>
+                <li data-i18n="processingPurposeItem5">technischer Betrieb, Fehleranalyse und Missbrauchsschutz</li>
+            </ul>
+        </section>
+
+        <section class="legal-card">
+            <h2 data-i18n="legalBasisTitle">3. Rechtsgrundlage</h2>
+            <p data-i18n="legalBasisText">
+                Soweit personenbezogene Daten verarbeitet werden, erfolgt dies in der Regel zur Bereitstellung der
+                Anwendung und ihrer Funktionen sowie aufgrund des berechtigten Interesses an einem sicheren und
+                funktionsfaehigen Webangebot. Falls eine ausdrückliche Einwilligung erforderlich ist, wird diese
+                gesondert eingeholt.
+            </p>
+        </section>
+
+        <section class="legal-card">
+            <h2 data-i18n="storageTitle">4. Speicherung und Löschung</h2>
+            <p data-i18n="storageText">
+                Personenbezogene Daten werden nur so lange gespeichert, wie sie für den jeweiligen Zweck benötigt
+                werden. Benutzerkonten und zugehörige Spielstände bleiben grundsätzlich gespeichert, bis sie
+                gelöscht oder für das Projekt nicht mehr benötigt werden.
+            </p>
+        </section>
+
+        <section class="legal-card">
+            <h2 data-i18n="thirdPartyTitle">5. Weitergabe an Dritte</h2>
+            <p data-i18n="thirdPartyText">
+                Eine Weitergabe personenbezogener Daten erfolgt nur, wenn dies für den Betrieb der Anwendung
+                erforderlich ist, etwa durch einen Hosting-Anbieter oder technische Dienstleister. Ansonsten werden
+                keine Daten weitergegeben.
+            </p>
+        </section>
+
+        <section class="legal-card">
+            <h2 data-i18n="rightsTitle">6. Rechte betroffener Personen</h2>
+            <p data-i18n="rightsText">Betroffene Personen haben im Rahmen des anwendbaren Datenschutzrechts insbesondere
+                das Recht auf:</p>
+            <ul class="legal-list">
+                <li data-i18n="rightsItem1">Auskunft über die verarbeiteten personenbezogenen Daten</li>
+                <li data-i18n="rightsItem2">Berichtigung unrichtiger Daten</li>
+                <li data-i18n="rightsItem3">Löschung oder Einschraenkung der Verarbeitung</li>
+                <li data-i18n="rightsItem4">Widerspruch gegen die Verarbeitung</li>
+                <li data-i18n="rightsItem5">Herausgabe der bereitgestellten Daten, soweit anwendbar</li>
+            </ul>
+        </section>
+
+        <section class="legal-card">
+            <h2 data-i18n="securityTitle">7. Datensicherheit</h2>
+            <p data-i18n="securityText">
+                Es werden technische und organisatorische Massnahmen getroffen, um gespeicherte Daten vor Verlust,
+                Missbrauch oder unberechtigtem Zugriff zu schuetzen. Dazu gehoeren insbesondere passwortgeschuetzte
+                Konten und die Möglichkeit, Zwei-Faktor-Authentifizierung zu aktivieren.
+            </p>
+        </section>
+
+        <section class="legal-card">
+            <h2 data-i18n="versionTitle">8. Stand</h2>
+            <p data-i18n="versionText">Stand dieser Vorlage: April 2026</p>
+        </section>
+    </main>
+
+    {% include "partials/footer.html" %}
+    <script src="{{ url_for('static', filename='js/language.js') }}" defer></script>
+    <script src="{{ url_for('static', filename='js/legal.js') }}" defer></script>
+</body>
+
+</html>

app/templates/sign_up.html

@@ -6,18 +6,19 @@
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <title>Sign Up</title>
     <link rel="stylesheet" href="{{ url_for('static', filename='css/login.css') }}">
+    <link rel="stylesheet" href="{{ url_for('static', filename='css/footer.css') }}">
 </head>
 
 <body>
     <nav class="auth-nav">
         <a class="brand" href="{{ url_for('main.home') }}">
             <span class="brand-mark">♛</span>
-            <span>8-Damen- und 8-Tuerme Solver</span>
+            <span data-i18n="navBrand">8-Damen- und 8-Türme Solver</span>
         </a>
 
         <ul class="nav-links">
-            <li><a href="{{ url_for('login.login') }}">Login</a></li>
-            <li><a href="{{ url_for('login.register') }}">Create account</a></li>
+            <li><a href="{{ url_for('login.login') }}" data-i18n="navLogin">Login</a></li>
+            <li><a href="{{ url_for('login.register') }}" data-i18n="navRegister">Create account</a></li>
         </ul>
     </nav>
 
@@ -51,6 +52,9 @@
         </section>
     </main>
 
+    {% include "partials/footer.html" %}
+
+    <script src="{{ url_for('static', filename='js/language.js') }}" defer></script>
     <script src="{{ url_for('static', filename='js/login.js') }}" defer></script>
 </body>
 

app/templates/two_factor_verify.html

@@ -6,18 +6,19 @@
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <title>Verify Login</title>
     <link rel="stylesheet" href="{{ url_for('static', filename='css/login.css') }}">
+    <link rel="stylesheet" href="{{ url_for('static', filename='css/footer.css') }}">
 </head>
 
 <body>
     <nav class="auth-nav">
         <a class="brand" href="{{ url_for('main.home') }}">
             <span class="brand-mark">♛</span>
-            <span>8-Damen- und 8-Tuerme Solver</span>
+            <span data-i18n="navBrand">8-Damen- und 8-Türme Solver</span>
         </a>
 
         <ul class="nav-links">
-            <li><a href="{{ url_for('login.login') }}">Login</a></li>
-            <li><a href="{{ url_for('login.register') }}">Create account</a></li>
+            <li><a href="{{ url_for('login.login') }}" data-i18n="navLogin">Login</a></li>
+            <li><a href="{{ url_for('login.register') }}" data-i18n="navRegister">Create account</a></li>
         </ul>
     </nav>
 
@@ -48,6 +49,9 @@
         </section>
     </main>
 
+    {% include "partials/footer.html" %}
+
+    <script src="{{ url_for('static', filename='js/language.js') }}" defer></script>
     <script src="{{ url_for('static', filename='js/login.js') }}" defer></script>
 </body>
 

passenger_wsgi.py

@@ -0,0 +1,16 @@
+import os
+import sys
+
+
+PROJECT_ROOT = os.path.dirname(os.path.abspath(__file__))
+
+if PROJECT_ROOT not in sys.path:
+    sys.path.insert(0, PROJECT_ROOT)
+
+os.chdir(PROJECT_ROOT)
+
+from app import create_app
+
+
+application = create_app()
+app = application