added step wise solution and an animation.

implemented "acht-damen algorithmus", seperated javascript from html,…

app/__init__.py

@@ -1,7 +1,8 @@
-from flask import Flask
 import os
-from flask_sqlalchemy import SQLAlchemy
+
+from flask import Flask
 from flask_login import LoginManager
+from flask_sqlalchemy import SQLAlchemy
 
 db = SQLAlchemy()
 login_manager = LoginManager()
@@ -20,6 +21,7 @@ def create_app():
     login_manager.login_view = "login.login"
 
     from .models.user import User
+    from .models.gamestate import GameState
 
     with app.app_context():
         db.create_all()

app/models/gamestate.py

@@ -0,0 +1,21 @@
+from .. import db
+
+class GameState(db.Model):
+    __tablename__ = "game_state"
+
+    id = db.Column(db.Integer, primary_key=True)
+    user_id = db.Column(db.Integer, nullable=False)
+
+    board = db.Column(db.Text, nullable=False)
+    mode = db.Column(db.String(10), nullable=False)
+    board_size = db.Column(db.Integer, nullable=False, default=8)
+    save_name = db.Column(db.String(80), nullable=False, default="Unnamed Save")
+    save_note = db.Column(db.Text, nullable=False, default="")
+    is_favorite = db.Column(db.Boolean, nullable=False, default=False)
+    created_at = db.Column(db.DateTime, nullable=False, server_default=db.func.now())
+    updated_at = db.Column(
+        db.DateTime,
+        nullable=False,
+        server_default=db.func.now(),
+        onupdate=db.func.now()
+    )

app/routes/login_routes.py

@@ -46,7 +46,7 @@ def login():
 
     return render_template("login.html")
 
-@login_bp.route('/logout')
+@login_bp.route('/logout', methods=['POST'])
 @login_required
 def logout():
     logout_user()

app/routes/main_routes.py

@@ -1,17 +1,227 @@
-from flask import Blueprint, jsonify, render_template, request
+import json
-from flask_login  import login_required, current_user
 import random
+from datetime import datetime
+
+from flask import Blueprint, jsonify, render_template, request
+from flask_login import current_user, login_required
+
+from .. import db
+from ..models.gamestate import GameState
+
+DEFAULT_BOARD_SIZE = 8
+MIN_BOARD_SIZE = 4
+MAX_BOARD_SIZE = 13
 
 main_bp = Blueprint("main", __name__)
 
+
+def parse_board_size(raw_size, default=DEFAULT_BOARD_SIZE):
+    try:
+        board_size = int(raw_size)
+    except (TypeError, ValueError):
+        board_size = default
+
+    return max(MIN_BOARD_SIZE, min(MAX_BOARD_SIZE, board_size))
+
+
+def parse_favorite_flag(raw_value):
+    return str(raw_value).lower() in {"1", "true", "yes", "on"}
+
+
+def get_position_label(row, col, board_size):
+    return f"{chr(65 + col)}{board_size - row}"
+
+
+def solve_queens(board_size):
+    queen_positions = [-1] * board_size
+    queen_solutions = []
+
+    def is_queen_position_safe(row, col):
+        for previous_row in range(row):
+            previous_col = queen_positions[previous_row]
+
+            if previous_col == col:
+                return False
+
+            if abs(previous_col - col) == abs(previous_row - row):
+                return False
+
+        return True
+
+    def place_queen(row):
+        if row == board_size:
+            queen_solutions.append(queen_positions[:])
+            return
+
+        for col in range(board_size):
+            if is_queen_position_safe(row, col):
+                queen_positions[row] = col
+                place_queen(row + 1)
+                queen_positions[row] = -1
+
+    place_queen(0)
+    return queen_solutions
+
+
+def solve_rooks(board_size):
+    rook_positions = list(range(board_size))
+    random.shuffle(rook_positions)
+    return rook_positions
+
+
+def build_queens_trace(board_size):
+    queen_positions = [-1] * board_size
+    steps = []
+
+    def is_queen_position_safe(row, col):
+        for previous_row in range(row):
+            previous_col = queen_positions[previous_row]
+
+            if previous_col == col:
+                return False
+
+            if abs(previous_col - col) == abs(previous_row - row):
+                return False
+
+        return True
+
+    def place_queen(row):
+        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."
+            })
+            return True
+
+        for col in range(board_size):
+            if not is_queen_position_safe(row, col):
+                continue
+
+            queen_positions[row] = col
+            position = get_position_label(row, col, board_size)
+            steps.append({
+                "type": "place",
+                "row": row,
+                "col": col,
+                "board": queen_positions[:],
+                "message": f"Dame auf {position} gesetzt."
+            })
+
+            if place_queen(row + 1):
+                return True
+
+            queen_positions[row] = -1
+            steps.append({
+                "type": "remove",
+                "row": row,
+                "col": col,
+                "board": queen_positions[:],
+                "message": f"Backtracking: Dame von {position} entfernt."
+            })
+
+        return False
+
+    solved = place_queen(0)
+
+    return {
+        "mode": "queens",
+        "board_size": board_size,
+        "initial_board": [-1] * board_size,
+        "steps": steps,
+        "solved": solved
+    }
+
+
+def build_rooks_trace(board_size):
+    rook_positions = solve_rooks(board_size)
+    board = [-1] * board_size
+    steps = []
+
+    for row, col in enumerate(rook_positions):
+        board[row] = col
+        position = get_position_label(row, col, board_size)
+        steps.append({
+            "type": "place",
+            "row": row,
+            "col": col,
+            "board": board[:],
+            "message": f"Turm auf {position} gesetzt."
+        })
+
+    steps.append({
+        "type": "solution",
+        "row": None,
+        "col": None,
+        "board": board[:],
+        "message": f"Loesung gefunden. Alle {board_size} Tuerme stehen ohne Konflikte."
+    })
+
+    return {
+        "mode": "rooks",
+        "board_size": board_size,
+        "initial_board": [-1] * board_size,
+        "steps": steps,
+        "solved": True
+    }
+
+
+def serialize_game_state(game_state):
+    board = json.loads(game_state.board)
+
+    return {
+        "id": game_state.id,
+        "board": board,
+        "mode": game_state.mode,
+        "board_size": game_state.board_size,
+        "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),
+        "created_at": game_state.created_at.strftime("%Y-%m-%d %H:%M:%S"),
+        "updated_at": game_state.updated_at.strftime("%Y-%m-%d %H:%M:%S")
+    }
+
+
+def build_save_point_query():
+    query = GameState.query.filter_by(user_id=current_user.id)
+
+    selected_mode = request.args.get("mode")
+    board_size = request.args.get("board_size")
+    favorites_only = request.args.get("favorites_only")
+    sort_by = request.args.get("sort", "newest")
+
+    if selected_mode in {"queens", "rooks"}:
+        query = query.filter_by(mode=selected_mode)
+
+    if board_size not in {None, "", "all"}:
+        query = query.filter_by(board_size=parse_board_size(board_size))
+
+    if parse_favorite_flag(favorites_only):
+        query = query.filter_by(is_favorite=True)
+
+    sort_options = {
+        "newest": GameState.created_at.desc(),
+        "oldest": GameState.created_at.asc(),
+        "updated": GameState.updated_at.desc(),
+        "favorites": GameState.is_favorite.desc()
+    }
+
+    return query.order_by(sort_options.get(sort_by, GameState.created_at.desc()), GameState.id.desc())
+
+
 @main_bp.route("/")
 def home():
     return render_template("index.html")
 
-@main_bp.route('/dashboard')
+
+@main_bp.route("/dashboard")
 @login_required
 def dashboard():
-    return render_template('dashboard.html', user=current_user)
+    return render_template("dashboard.html", user=current_user)
+
 
 @main_bp.route("/check", methods=["POST"])
 def check():
@@ -19,57 +229,138 @@ def check():
     board = data["board"]
     row = data["row"]
     col = data["col"]
+    piece_mode = data.get("mode", "queens")
 
-    for r in range(len(board)):
+    for current_row, current_col in enumerate(board):
-        c = board[r]
+        if current_col == -1 or current_row == row:
-
-        if c == -1 or r == row:
             continue
 
-        # gleiche Spalte
+        same_column = current_col == col
-        if c == col:
+        same_diagonal = abs(current_col - col) == abs(current_row - row)
+
+        if same_column:
             return jsonify({"valid": False})
 
-        # gleiche Diagonale
+        if piece_mode == "queens" and same_diagonal:
-        if abs(c - col) == abs(r - row):
             return jsonify({"valid": False})
 
     return jsonify({"valid": True})
 
 
 @main_bp.route("/solve")
-def solve():
+def solve_queens_route():
-    n = 8
+    board_size = parse_board_size(request.args.get("size"))
-    solutions = []
+    return jsonify(solve_queens(board_size))
-    board = [-1] * n
 
-    def is_safe(row, col):
-        for r in range(row):
-            c = board[r]
-            if c == col or abs(c - col) == abs(r - row):
-                return False
-        return True
 
-    def backtrack(row):
+@main_bp.route("/solve_trace")
-        if row == n:
+def solve_queens_trace_route():
-            solutions.append(board[:])
+    board_size = parse_board_size(request.args.get("size"))
-            return
+    return jsonify(build_queens_trace(board_size))
 
-        for col in range(n):
-            if is_safe(row, col):
-                board[row] = col
-                backtrack(row + 1)
-                board[row] = -1
-
-    backtrack(0)
-    return jsonify(solutions)
 
 @main_bp.route("/solve_rooks")
 def solve_rooks_route():
-    return jsonify(solve_rooks(8))
+    board_size = parse_board_size(request.args.get("size"))
+    return jsonify(solve_rooks(board_size))
 
-def solve_rooks(n=8):
-    solution = list(range(n))
-    random.shuffle(solution)
-    return solution
 
+@main_bp.route("/solve_rooks_trace")
+def solve_rooks_trace_route():
+    board_size = parse_board_size(request.args.get("size"))
+    return jsonify(build_rooks_trace(board_size))
+
+
+@main_bp.route("/save", methods=["POST"])
+@login_required
+def save_game():
+    data = request.json
+
+    board = data["board"]
+    piece_mode = data["mode"]
+    board_size = parse_board_size(data.get("boardSize"), default=len(board))
+    save_name = (data.get("saveName") or "").strip() or f"{piece_mode.title()} Save"
+    save_note = (data.get("saveNote") or "").strip()
+    is_favorite = bool(data.get("isFavorite"))
+    timestamp = datetime.utcnow()
+
+    game_state = GameState(
+        user_id=current_user.id,
+        board=json.dumps(board),
+        mode=piece_mode,
+        board_size=board_size,
+        save_name=save_name,
+        save_note=save_note,
+        is_favorite=is_favorite,
+        created_at=timestamp,
+        updated_at=timestamp
+    )
+
+    db.session.add(game_state)
+    db.session.commit()
+
+    return jsonify({
+        "status": "saved",
+        "save_point": serialize_game_state(game_state)
+    })
+
+
+@main_bp.route("/save_points")
+@login_required
+def list_save_points():
+    save_points = build_save_point_query().all()
+    return jsonify([serialize_game_state(game_state) for game_state in save_points])
+
+
+@main_bp.route("/save_points/<int:game_id>/favorite", methods=["POST"])
+@login_required
+def toggle_save_point_favorite(game_id):
+    game_state = GameState.query.filter_by(id=game_id, user_id=current_user.id).first()
+
+    if not game_state:
+        return jsonify({"error": "Save point not found"}), 404
+
+    game_state.is_favorite = not game_state.is_favorite
+    db.session.commit()
+
+    return jsonify(serialize_game_state(game_state))
+
+
+@main_bp.route("/save_points/<int:game_id>", methods=["DELETE"])
+@login_required
+def delete_save_point(game_id):
+    game_state = GameState.query.filter_by(id=game_id, user_id=current_user.id).first()
+
+    if not game_state:
+        return jsonify({"error": "Save point not found"}), 404
+
+    db.session.delete(game_state)
+    db.session.commit()
+
+    return jsonify({"status": "deleted"})
+
+
+@main_bp.route("/load")
+@login_required
+def load_game():
+    latest_game = (
+        GameState.query.filter_by(user_id=current_user.id)
+        .order_by(GameState.created_at.desc(), GameState.id.desc())
+        .first()
+    )
+
+    if not latest_game:
+        return jsonify({"board": [-1] * DEFAULT_BOARD_SIZE, "mode": "queens"})
+
+    return jsonify(serialize_game_state(latest_game))
+
+
+@main_bp.route("/load/<int:game_id>")
+@login_required
+def load_specific_game(game_id):
+    game_state = GameState.query.filter_by(id=game_id, user_id=current_user.id).first()
+
+    if not game_state:
+        return jsonify({"error": "Save point not found"}), 404
+
+    return jsonify(serialize_game_state(game_state))

app/static/css/dashboard.css

@@ -44,16 +44,30 @@ body {
     text-align: center;
 }
 
+#statusMessage {
+    min-height: 24px;
+    margin: 0 0 8px;
+    font-weight: bold;
+}
+
+.board {
+    overflow-x: auto;
+    padding-bottom: 8px;
+}
+
 /* ♟️ Board */
 .board-grid {
+    --label-size: 30px;
+    --cell-size: 60px;
     display: grid;
-    grid-template-columns: 30px repeat(8, 60px);
+    grid-template-columns: var(--label-size) repeat(var(--board-size, 8), var(--cell-size));
-    grid-template-rows: 30px repeat(8, 60px);
+    grid-template-rows: var(--label-size) repeat(var(--board-size, 8), var(--cell-size));
     margin: 20px auto;
     width: max-content;
     border: 6px solid #1e293b;
     border-radius: 10px;
     overflow: hidden;
+    max-width: 100%;
 }
 
 .label {
@@ -63,17 +77,18 @@ body {
     font-weight: bold;
     background: #aec8eb;
     color: #1e293b;
+    width: var(--label-size);
+    height: var(--label-size);
+    font-size: 14px;
 }
 
-
-
 .cell {
-    width: 60px;
+    width: var(--cell-size);
-    height: 60px;
+    height: var(--cell-size);
     display: flex;
     align-items: center;
     justify-content: center;
-    font-size: 30px;
+    font-size: calc(var(--cell-size) * 0.5);
     cursor: pointer;
     transition: 0.2s;
 }
@@ -82,6 +97,21 @@ body {
     transform: scale(1.05);
 }
 
+.cell.solver-place {
+    box-shadow: inset 0 0 0 4px #22c55e;
+    animation: solverPulse 0.35s ease;
+}
+
+.cell.solver-remove {
+    box-shadow: inset 0 0 0 4px #f59e0b;
+    animation: solverPulse 0.35s ease;
+}
+
+.cell.solver-solution {
+    box-shadow: inset 0 0 0 4px #2563eb;
+    animation: solverPulse 0.35s ease;
+}
+
 .white {
     background: #e2e8f0;
 }
@@ -98,6 +128,10 @@ body {
 /* 🎛️ Buttons */
 .controls {
     margin-top: 15px;
+    display: flex;
+    justify-content: center;
+    flex-wrap: wrap;
+    gap: 10px;
 }
 
 .btn {
@@ -114,6 +148,12 @@ body {
     background: #2563eb;
 }
 
+.btn:disabled,
+.btn:disabled:hover {
+    background: #94a3b8;
+    cursor: not-allowed;
+}
+
 .btn.secondary {
     background: #64748b;
 }
@@ -153,3 +193,281 @@ body {
 .btn.active {
     background: #22c55e;
 }
+
+.solver-panel {
+    margin-top: 12px;
+    padding: 16px;
+    border-radius: 12px;
+    border: 1px solid #dbe4ee;
+    background: #f8fafc;
+    text-align: left;
+}
+
+.solver-panel-header {
+    display: flex;
+    justify-content: space-between;
+    align-items: flex-start;
+    gap: 16px;
+}
+
+.solver-panel h3 {
+    margin: 0 0 6px;
+    color: #1e293b;
+}
+
+.solver-message {
+    margin: 0;
+    color: #475569;
+}
+
+.solver-step-info {
+    margin: 0;
+    padding: 6px 10px;
+    border-radius: 999px;
+    background: #dbeafe;
+    color: #1d4ed8;
+    font-size: 14px;
+    font-weight: bold;
+    white-space: nowrap;
+}
+
+.solver-controls {
+    display: flex;
+    flex-wrap: wrap;
+    gap: 10px;
+    margin-top: 14px;
+}
+
+.solver-controls .btn,
+.controls .btn {
+    margin: 0;
+}
+
+.solver-speed {
+    display: grid;
+    grid-template-columns: auto 1fr auto;
+    align-items: center;
+    gap: 12px;
+    margin-top: 14px;
+}
+
+.solver-speed input[type="range"] {
+    width: 100%;
+}
+
+.solver-speed-label {
+    font-weight: bold;
+    color: #334155;
+}
+
+.solver-speed-value {
+    min-width: 62px;
+    text-align: right;
+    color: #475569;
+    font-variant-numeric: tabular-nums;
+}
+
+.board-size-info {
+    margin: 0 0 10px;
+    color: #475569;
+}
+
+.sidebar {
+    position: fixed;
+    top: 0;
+    right: 0;
+    width: min(320px, 85vw);
+    height: 100vh;
+    padding: 24px;
+    box-sizing: border-box;
+    background: white;
+    box-shadow: -10px 0 24px rgba(15, 23, 42, 0.18);
+    transform: translateX(100%);
+    transition: transform 0.25s ease;
+    overflow-y: auto;
+    -webkit-overflow-scrolling: touch;
+    overscroll-behavior: contain;
+    z-index: 30;
+}
+
+.sidebar.open {
+    transform: translateX(0);
+}
+
+.save-points-sidebar {
+    width: min(380px, 92vw);
+}
+
+.save-sidebar {
+    width: min(360px, 90vw);
+}
+
+.sidebar-header {
+    display: flex;
+    justify-content: space-between;
+    align-items: center;
+    gap: 10px;
+}
+
+.sidebar-close {
+    margin: 0;
+}
+
+.sidebar-label {
+    display: block;
+    margin-top: 18px;
+    margin-bottom: 8px;
+    font-weight: bold;
+}
+
+.sidebar input[type="range"] {
+    width: 100%;
+}
+
+.sidebar-input {
+    width: 100%;
+    padding: 10px 12px;
+    border: 1px solid #cbd5e1;
+    border-radius: 8px;
+    font: inherit;
+    box-sizing: border-box;
+    background: #fff;
+}
+
+.sidebar-textarea {
+    resize: vertical;
+    min-height: 96px;
+}
+
+.sidebar-checkbox {
+    display: flex;
+    align-items: center;
+    gap: 10px;
+    margin: 16px 0 18px;
+    color: #334155;
+}
+
+.sidebar-size-row {
+    margin: 12px 0 18px;
+    font-size: 18px;
+}
+
+.sidebar-hint {
+    color: #64748b;
+    font-size: 14px;
+}
+
+.save-points-list {
+    display: grid;
+    gap: 12px;
+    margin-top: 18px;
+}
+
+.save-point-filters {
+    display: grid;
+    gap: 8px;
+    margin-top: 18px;
+    padding-bottom: 16px;
+    border-bottom: 1px solid #e2e8f0;
+}
+
+.save-point-card {
+    border: 1px solid #dbe4ee;
+    border-radius: 10px;
+    padding: 14px;
+    background: #f8fafc;
+}
+
+.save-point-card h4 {
+    margin: 0 0 8px;
+    color: #1e293b;
+}
+
+.save-point-meta {
+    margin: 4px 0;
+    color: #475569;
+    font-size: 14px;
+}
+
+.save-point-preview {
+    margin: 10px 0 0;
+    color: #334155;
+    font-size: 14px;
+    word-break: break-word;
+}
+
+.save-point-note {
+    margin: 10px 0 0;
+    color: #475569;
+    font-size: 14px;
+}
+
+.save-point-actions {
+    display: flex;
+    flex-wrap: wrap;
+    gap: 8px;
+    margin-top: 14px;
+}
+
+.save-point-actions .btn {
+    margin: 0;
+}
+
+.btn.ghost {
+    background: #e2e8f0;
+    color: #1e293b;
+}
+
+.btn.ghost:hover {
+    background: #cbd5e1;
+}
+
+.sidebar-backdrop {
+    position: fixed;
+    inset: 0;
+    background: rgba(15, 23, 42, 0.3);
+    opacity: 0;
+    pointer-events: none;
+    transition: opacity 0.25s ease;
+    z-index: 20;
+}
+
+.sidebar-backdrop.visible {
+    opacity: 1;
+    pointer-events: auto;
+}
+
+@keyframes solverPulse {
+    0% {
+        transform: scale(0.97);
+    }
+
+    50% {
+        transform: scale(1.03);
+    }
+
+    100% {
+        transform: scale(1);
+    }
+}
+
+@media (max-width: 720px) {
+    .container {
+        padding: 12px;
+    }
+
+    .navbar {
+        padding: 15px 18px;
+    }
+
+    .solver-panel-header,
+    .solver-speed {
+        grid-template-columns: 1fr;
+        display: grid;
+    }
+
+    .solver-step-info,
+    .solver-speed-value {
+        justify-self: start;
+    }
+}

app/static/js/dashboard.js

@@ -1,53 +1,215 @@
-let mode = "queens"; // oder "rooks"
+const DEFAULT_BOARD_SIZE = 8;
+const MIN_BOARD_SIZE = 4;
+const MAX_BOARD_SIZE = 13;
+const EMPTY_CELL = -1;
+const DEFAULT_SOLVER_MESSAGE = "Bereite einen Ablauf vor und spiele ihn Schritt fuer Schritt ab.";
 
-function setMode(newMode) {
+let mode = "queens";
-    mode = newMode;
+let boardSize = DEFAULT_BOARD_SIZE;
-    resetBoard();
+let pendingBoardSize = DEFAULT_BOARD_SIZE;
+let board = createEmptyBoard(boardSize);
 
-    document.getElementById("btnQueens").classList.remove("active");
+let solverSteps = [];
-    document.getElementById("btnRooks").classList.remove("active");
+let solverStepIndex = -1;
+let solverTimerId = null;
+let solverSpeedMs = 320;
+let solverLoading = false;
+let solverRequestId = 0;
+let currentSolverHighlight = null;
 
-    if (mode === "queens") {
+const boardDiv = document.getElementById("board");
-        document.getElementById("btnQueens").classList.add("active");
+const statusMessage = document.getElementById("statusMessage");
-    } else {
+const queenList = document.getElementById("queenList");
-        document.getElementById("btnRooks").classList.add("active");
+const btnQueens = document.getElementById("btnQueens");
-    }
+const btnRooks = document.getElementById("btnRooks");
+const btnPrepareSolve = document.getElementById("btnPrepareSolve");
+const btnInstantSolve = document.getElementById("btnInstantSolve");
+const btnNextStep = document.getElementById("btnNextStep");
+const btnPlayPause = document.getElementById("btnPlayPause");
+const solverMessage = document.getElementById("solverMessage");
+const solverStepInfo = document.getElementById("solverStepInfo");
+const solverSpeedInput = document.getElementById("solverSpeedInput");
+const solverSpeedValue = document.getElementById("solverSpeedValue");
+const settingsSidebar = document.getElementById("settingsSidebar");
+const sidebarBackdrop = document.getElementById("sidebarBackdrop");
+const saveSidebar = document.getElementById("saveSidebar");
+const saveBackdrop = document.getElementById("saveBackdrop");
+const savePointsSidebar = document.getElementById("savePointsSidebar");
+const savePointsBackdrop = document.getElementById("savePointsBackdrop");
+const boardSizeInput = document.getElementById("boardSizeInput");
+const boardSizeValue = document.getElementById("boardSizeValue");
+const boardSizeValueMirror = document.getElementById("boardSizeValueMirror");
+const sidebarBoardSizeValue = document.getElementById("sidebarBoardSizeValue");
+const sidebarBoardSizeValueMirror = document.getElementById("sidebarBoardSizeValueMirror");
+const savePointsList = document.getElementById("savePointsList");
+const saveNameInput = document.getElementById("saveNameInput");
+const saveNoteInput = document.getElementById("saveNoteInput");
+const saveFavoriteInput = document.getElementById("saveFavoriteInput");
+const savePointModeFilter = document.getElementById("savePointModeFilter");
+const savePointSizeFilter = document.getElementById("savePointSizeFilter");
+const savePointSortFilter = document.getElementById("savePointSortFilter");
+const savePointFavoritesOnly = document.getElementById("savePointFavoritesOnly");
 
-    drawBoard();
+function createEmptyBoard(size) {
+    return Array(size).fill(EMPTY_CELL);
 }
 
-let board = Array(8).fill(-1);
+function clampBoardSize(size) {
-const boardDiv = document.getElementById("board");
+    return Math.min(MAX_BOARD_SIZE, Math.max(MIN_BOARD_SIZE, Number(size)));
+}
+
+function getColumnLabel(index) {
+    return String.fromCharCode(65 + index);
+}
+
+function updateModeButtons() {
+    btnQueens.classList.toggle("active", mode === "queens");
+    btnRooks.classList.toggle("active", mode === "rooks");
+}
+
+function updateBoardSizeDisplays(size) {
+    boardSizeValue.textContent = size;
+    boardSizeValueMirror.textContent = size;
+    sidebarBoardSizeValue.textContent = size;
+    sidebarBoardSizeValueMirror.textContent = size;
+    boardSizeInput.value = size;
+}
+
+function setStatus(message = "", color = "") {
+    statusMessage.textContent = message;
+    statusMessage.style.color = color;
+}
+
+function setSolverMessage(message = DEFAULT_SOLVER_MESSAGE) {
+    solverMessage.textContent = message;
+}
+
+function updateSolverSpeed(rawValue) {
+    solverSpeedMs = Number(rawValue);
+    solverSpeedInput.value = String(solverSpeedMs);
+    solverSpeedValue.textContent = `${solverSpeedMs} ms`;
+
+    if (isSolverPlaying()) {
+        stopSolverPlayback(false);
+        scheduleNextSolverPlaybackStep();
+    }
+}
+
+function updateBoardLayout() {
+    const cellSize = Math.max(32, Math.min(60, Math.floor(480 / boardSize)));
+
+    boardDiv.style.setProperty("--board-size", boardSize);
+    boardDiv.style.setProperty("--cell-size", `${cellSize}px`);
+}
+
+function isSolverPlaying() {
+    return solverTimerId !== null;
+}
+
+function hasPreparedSolverTrace() {
+    return solverSteps.length > 0;
+}
+
+function hasCompletedSolverTrace() {
+    return hasPreparedSolverTrace() && solverStepIndex >= solverSteps.length - 1;
+}
+
+function stopSolverPlayback(refreshControls = true) {
+    if (solverTimerId !== null) {
+        window.clearTimeout(solverTimerId);
+        solverTimerId = null;
+    }
+
+    if (refreshControls) {
+        updateSolverControls();
+    }
+}
+
+function updateSolverControls() {
+    const currentStep = Math.max(0, solverStepIndex + 1);
+
+    btnPrepareSolve.disabled = solverLoading;
+    btnInstantSolve.disabled = solverLoading;
+    btnNextStep.disabled = solverLoading || hasCompletedSolverTrace();
+    btnPlayPause.disabled = solverLoading;
+
+    btnPrepareSolve.textContent = solverLoading ? "Preparing..." : "Solve Step-by-Step";
+
+    if (isSolverPlaying()) {
+        btnPlayPause.textContent = "Pause";
+    } else if (hasCompletedSolverTrace()) {
+        btnPlayPause.textContent = "Replay Animation";
+    } else {
+        btnPlayPause.textContent = "Play Animation";
+    }
+
+    solverStepInfo.textContent = `Schritt ${currentStep} / ${solverSteps.length}`;
+}
+
+function discardSolverTrace(message = DEFAULT_SOLVER_MESSAGE) {
+    solverRequestId += 1;
+    solverLoading = false;
+    stopSolverPlayback(false);
+
+    solverSteps = [];
+    solverStepIndex = -1;
+    currentSolverHighlight = null;
+
+    setSolverMessage(message);
+    updateSolverControls();
+}
+
+function rewindSolverTrace() {
+    stopSolverPlayback(false);
+    solverStepIndex = -1;
+    currentSolverHighlight = null;
+    board = createEmptyBoard(boardSize);
+    setSolverMessage("Ablauf zurueckgesetzt. Starte die Animation erneut oder gehe weiter mit Next Step.");
+    drawBoard();
+    updateSolverControls();
+}
+
+function setMode(newMode) {
+    if (mode === newMode) {
+        return;
+    }
+
+    mode = newMode;
+    updateModeButtons();
+    resetBoard({
+        statusMessageText: `${getPieceLabel(mode)}-Modus aktiviert.`,
+        statusColor: "#2563eb",
+        solverMessageText: `${getPieceLabel(mode)}-Solver bereit. ${DEFAULT_SOLVER_MESSAGE}`
+    });
+}
+
+function closeAllPanels() {
+    toggleSidebar(false);
+    toggleSavePanel(false);
+    toggleSavePointsPanel(false);
+}
 
 function getConflicts() {
-    let conflicts = [];
+    const conflicts = [];
 
-    for (let r1 = 0; r1 < 8; r1++) {
+    for (let rowA = 0; rowA < boardSize; rowA++) {
-        if (board[r1] === -1) continue;
+        if (board[rowA] === EMPTY_CELL) {
+            continue;
+        }
 
-        for (let r2 = r1 + 1; r2 < 8; r2++) {
+        for (let rowB = rowA + 1; rowB < boardSize; rowB++) {
-            if (board[r2] === -1) continue;
+            if (board[rowB] === EMPTY_CELL) {
-
+                continue;
-            let c1 = board[r1];
-            let c2 = board[r2];
-
-            // 🔴 Türme: nur gleiche Spalte
-            if (mode === "rooks") {
-                if (c1 === c2) {
-                    conflicts.push([r1, c1]);
-                    conflicts.push([r2, c2]);
-                }
             }
 
-            // 🔴 Damen: Spalte + Diagonale
+            const colA = board[rowA];
-            else if (mode === "queens") {
+            const colB = board[rowB];
-                if (
+            const sameColumn = colA === colB;
-                    c1 === c2 ||
+            const sameDiagonal = Math.abs(colA - colB) === Math.abs(rowA - rowB);
-                    Math.abs(c1 - c2) === Math.abs(r1 - r2)
+            const hasConflict = mode === "rooks" ? sameColumn : sameColumn || sameDiagonal;
-                ) {
+
-                    conflicts.push([r1, c1]);
+            if (hasConflict) {
-                    conflicts.push([r2, c2]);
+                conflicts.push([rowA, colA], [rowB, colB]);
-                }
             }
         }
     }
@@ -56,71 +218,58 @@ function getConflicts() {
 }
 
 function checkSolution() {
-    const status = document.getElementById("statusMessage");
+    const allPlaced = board.every((col) => col !== EMPTY_CELL);
-
-    const allPlaced = board.every(col => col !== -1);
 
     if (!allPlaced) {
-        status.textContent = "❗ Noch nicht alle Figuren platziert.";
+        setStatus("Noch nicht alle Figuren platziert.", "#d97706");
-        status.style.color = "orange";
         return;
     }
 
-    const conflicts = getConflicts();
+    if (getConflicts().length > 0) {
-
+        setStatus("Es gibt Konflikte auf dem Brett.", "red");
-    if (conflicts.length > 0) {
-        status.textContent = "❌ Es gibt Konflikte!";
-        status.style.color = "red";
         return;
     }
 
-    status.textContent = "🎉 Perfekt gelöst!";
+    setStatus("Perfekt geloest.", "green");
-    status.style.color = "green";
 }
 
 function drawBoard() {
     boardDiv.innerHTML = "";
     boardDiv.className = "board-grid";
+    updateBoardLayout();
 
     const conflicts = getConflicts();
-    const letters = ["A", "B", "C", "D", "E", "F", "G", "H"];
+    const highlight = currentSolverHighlight;
-
-    for (let row = -1; row < 8; row++) {
-        for (let col = -1; col < 8; col++) {
 
+    for (let row = -1; row < boardSize; row++) {
+        for (let col = -1; col < boardSize; col++) {
             const cell = document.createElement("div");
 
-            // 🔹 Ecke oben links
             if (row === -1 && col === -1) {
                 cell.classList.add("label");
-            }
+            } else if (row === -1) {
-
+                cell.textContent = getColumnLabel(col);
-            // 🔹 Buchstaben (oben)
-            else if (row === -1) {
-                cell.textContent = letters[col];
                 cell.classList.add("label");
-            }
+            } else if (col === -1) {
-
+                cell.textContent = boardSize - row;
-            // 🔹 Zahlen (links)
-            else if (col === -1) {
-                cell.textContent = 8 - row;
                 cell.classList.add("label");
-            }
+            } else {
+                cell.classList.add("cell", (row + col) % 2 === 0 ? "white" : "black");
 
-            // 🔹 echtes Spielfeld
+                if (highlight && highlight.row === row && highlight.col === col) {
-            else {
+                    cell.classList.add(
-                cell.classList.add("cell");
+                        highlight.type === "remove"
-
+                            ? "solver-remove"
-                if ((row + col) % 2 === 0) {
+                            : highlight.type === "solution"
-                    cell.classList.add("white");
+                                ? "solver-solution"
-                } else {
+                                : "solver-place"
-                    cell.classList.add("black");
+                    );
                 }
 
                 if (board[row] === col) {
-                    cell.textContent = (mode === "queens") ? "♛" : "♜";
+                    cell.textContent = mode === "queens" ? "♛" : "♜";
 
-                    if (conflicts.some(([r, c]) => r === row && c === col)) {
+                    if (conflicts.some(([conflictRow, conflictCol]) => conflictRow === row && conflictCol === col)) {
                         cell.classList.add("invalid");
                     }
                 }
@@ -136,64 +285,596 @@ function drawBoard() {
 }
 
 function placeQueen(row, col) {
-    if (board[row] === col) {
+    if (solverLoading) {
-        board[row] = -1;
-    } else {
-        board[row] = col;
-    }
-    drawBoard();
-    updateQueenList();
-}
-
-async function solve() {
-
-    if (mode === "rooks") {
-        const res = await fetch("/solve_rooks");
-        const solution = await res.json();
-
-        board = solution;
-        drawBoard();
         return;
     }
 
-    // Damen (wie vorher)
+    if (hasPreparedSolverTrace() || isSolverPlaying()) {
-    const res = await fetch("/solve");
+        discardSolverTrace("Solver-Ablauf verworfen, weil das Brett manuell geaendert wurde.");
-    const solution = await res.json();
+        setStatus("Solver-Ablauf verworfen. Bereite ihn bei Bedarf neu vor.", "#d97706");
+    } else {
+        setStatus();
+    }
 
-    board = Array.isArray(solution[0]) ? solution[0] : solution;
+    currentSolverHighlight = null;
+    board[row] = board[row] === col ? EMPTY_CELL : col;
     drawBoard();
 }
 
-
+function previewBoardSize(size) {
-function resetBoard() {
+    pendingBoardSize = clampBoardSize(size);
-    const status = document.getElementById("statusMessage");
+    sidebarBoardSizeValue.textContent = pendingBoardSize;
-    board = Array(8).fill(-1);
+    sidebarBoardSizeValueMirror.textContent = pendingBoardSize;
-    drawBoard();
-    updateQueenList();
-    status.textContent = "";
 }
 
-drawBoard();
+function applyBoardSize() {
+    boardSize = pendingBoardSize;
+    discardSolverTrace(`${getPieceLabel(mode)}-Solver bereit. ${DEFAULT_SOLVER_MESSAGE}`);
+    board = createEmptyBoard(boardSize);
+    currentSolverHighlight = null;
+    updateBoardSizeDisplays(boardSize);
+    setStatus(`Brettgroesse auf ${boardSize} x ${boardSize} gesetzt.`, "#2563eb");
+    drawBoard();
+    toggleSidebar(false);
+}
 
-function updateQueenList() {
+function toggleSidebar(forceOpen) {
-    const list = document.getElementById("queenList");
+    const shouldOpen = typeof forceOpen === "boolean" ? forceOpen : !settingsSidebar.classList.contains("open");
-    list.innerHTML = "";
 
-    const letters = ["A", "B", "C", "D", "E", "F", "G", "H"];
+    if (shouldOpen) {
+        toggleSavePanel(false);
+        toggleSavePointsPanel(false);
+    }
 
-    let count = 1;
+    settingsSidebar.classList.toggle("open", shouldOpen);
+    sidebarBackdrop.classList.toggle("visible", shouldOpen);
+    settingsSidebar.setAttribute("aria-hidden", String(!shouldOpen));
+}
 
-    for (let row = 0; row < 8; row++) {
+function toggleSavePanel(forceOpen) {
-        if (board[row] !== -1) {
+    const shouldOpen = typeof forceOpen === "boolean" ? forceOpen : !saveSidebar.classList.contains("open");
-            let col = board[row];
 
-            let pos = letters[col] + (8 - row);
+    if (shouldOpen) {
+        toggleSidebar(false);
+        toggleSavePointsPanel(false);
+    }
 
-            const li = document.createElement("li");
+    saveSidebar.classList.toggle("open", shouldOpen);
-            li.textContent = `${mode === "queens" ? "Dame" : "Turm"} ${count}: ${pos}`;
+    saveBackdrop.classList.toggle("visible", shouldOpen);
+    saveSidebar.setAttribute("aria-hidden", String(!shouldOpen));
+}
 
-            list.appendChild(li);
+function toggleSavePointsPanel(forceOpen) {
-            count++;
+    const shouldOpen = typeof forceOpen === "boolean" ? forceOpen : !savePointsSidebar.classList.contains("open");
+
+    if (shouldOpen) {
+        toggleSidebar(false);
+        toggleSavePanel(false);
+    }
+
+    savePointsSidebar.classList.toggle("open", shouldOpen);
+    savePointsBackdrop.classList.toggle("visible", shouldOpen);
+    savePointsSidebar.setAttribute("aria-hidden", String(!shouldOpen));
+}
+
+function getPieceLabel(selectedMode) {
+    return selectedMode === "queens" ? "Dame" : "Turm";
+}
+
+function getPlacedPieceCount() {
+    return board.filter((col) => col !== EMPTY_CELL).length;
+}
+
+function resetSaveForm() {
+    saveNameInput.value = `${getPieceLabel(mode)} ${boardSize}x${boardSize} - ${getPlacedPieceCount()} gesetzt`;
+    saveNoteInput.value = "";
+    saveFavoriteInput.checked = false;
+}
+
+function openSavePanel() {
+    resetSaveForm();
+    toggleSavePanel(true);
+}
+
+function getBoardPreview(savedBoard, limit = 4) {
+    const preview = [];
+
+    for (let row = 0; row < savedBoard.length; row++) {
+        if (savedBoard[row] === EMPTY_CELL) {
+            continue;
+        }
+
+        preview.push(`${getColumnLabel(savedBoard[row])}${savedBoard.length - row}`);
+
+        if (preview.length === limit) {
+            break;
+        }
+    }
+
+    return preview.length > 0 ? preview.join(", ") : "Noch keine Figuren gesetzt";
+}
+
+function getSavePointFilters() {
+    const params = new URLSearchParams();
+
+    if (savePointModeFilter.value !== "all") {
+        params.set("mode", savePointModeFilter.value);
+    }
+
+    if (savePointSizeFilter.value !== "all") {
+        params.set("board_size", savePointSizeFilter.value);
+    }
+
+    params.set("sort", savePointSortFilter.value);
+
+    if (savePointFavoritesOnly.checked) {
+        params.set("favorites_only", "true");
+    }
+
+    return params.toString();
+}
+
+function createSavePointActionButton(label, className, onClick) {
+    const button = document.createElement("button");
+    button.className = className;
+    button.type = "button";
+    button.textContent = label;
+    button.onclick = onClick;
+    return button;
+}
+
+function renderSavePoints(savePoints) {
+    savePointsList.innerHTML = "";
+
+    if (savePoints.length === 0) {
+        savePointsList.innerHTML = '<p class="sidebar-hint">Keine Speicherstaende fuer diese Filter gefunden.</p>';
+        return;
+    }
+
+    for (const savePoint of savePoints) {
+        const item = document.createElement("article");
+        const title = document.createElement("h4");
+        const createdAt = document.createElement("p");
+        const updatedAt = document.createElement("p");
+        const boardMeta = document.createElement("p");
+        const preview = document.createElement("p");
+        const note = document.createElement("p");
+        const actions = document.createElement("div");
+
+        item.className = "save-point-card";
+        title.textContent = `${savePoint.is_favorite ? "★ " : ""}${savePoint.save_name}`;
+        createdAt.className = "save-point-meta";
+        createdAt.textContent = `Erstellt: ${savePoint.created_at}`;
+        updatedAt.className = "save-point-meta";
+        updatedAt.textContent = `Aktualisiert: ${savePoint.updated_at}`;
+        boardMeta.className = "save-point-meta";
+        boardMeta.textContent = `${getPieceLabel(savePoint.mode)} | ${savePoint.board_size} x ${savePoint.board_size} | ${savePoint.pieces_placed}/${savePoint.board_size} gesetzt`;
+        preview.className = "save-point-preview";
+        preview.textContent = `Vorschau: ${getBoardPreview(savePoint.board)}`;
+        note.className = "save-point-note";
+        note.textContent = savePoint.save_note ? `Notiz: ${savePoint.save_note}` : "Notiz: Keine Notiz";
+        actions.className = "save-point-actions";
+
+        actions.appendChild(createSavePointActionButton("Laden", "btn", () => loadSavePoint(savePoint.id)));
+        actions.appendChild(createSavePointActionButton(
+            savePoint.is_favorite ? "Favorit entfernen" : "Als Favorit",
+            "btn secondary",
+            () => toggleSavePointFavorite(savePoint.id)
+        ));
+        actions.appendChild(createSavePointActionButton("Loeschen", "btn ghost", () => deleteSavePoint(savePoint.id)));
+
+        item.appendChild(title);
+        item.appendChild(createdAt);
+        item.appendChild(updatedAt);
+        item.appendChild(boardMeta);
+        item.appendChild(preview);
+        item.appendChild(note);
+        item.appendChild(actions);
+        savePointsList.appendChild(item);
+    }
+}
+
+async function refreshSavePoints() {
+    const queryString = getSavePointFilters();
+    const response = await fetch(`/save_points${queryString ? `?${queryString}` : ""}`);
+    const savePoints = await response.json();
+    renderSavePoints(savePoints);
+}
+
+async function openSavePointsPanel() {
+    await refreshSavePoints();
+    toggleSavePointsPanel(true);
+}
+
+function applyLoadedGame(data) {
+    discardSolverTrace(`${getPieceLabel(data.mode || "queens")}-Solver bereit. ${DEFAULT_SOLVER_MESSAGE}`);
+
+    board = Array.isArray(data.board) ? data.board.slice() : createEmptyBoard(DEFAULT_BOARD_SIZE);
+    boardSize = Array.isArray(data.board) ? clampBoardSize(data.board.length) : DEFAULT_BOARD_SIZE;
+    pendingBoardSize = boardSize;
+    mode = data.mode === "rooks" ? "rooks" : "queens";
+    currentSolverHighlight = null;
+
+    updateModeButtons();
+    updateBoardSizeDisplays(boardSize);
+    drawBoard();
+}
+
+function applySolverStep(step) {
+    board = Array.isArray(step.board) ? step.board.slice() : createEmptyBoard(boardSize);
+
+    if (Number.isInteger(step.row) && Number.isInteger(step.col)) {
+        currentSolverHighlight = {
+            row: step.row,
+            col: step.col,
+            type: step.type
+        };
+    } else if (step.type === "solution" && solverStepIndex > 0) {
+        const previousStep = solverSteps[solverStepIndex - 1];
+        currentSolverHighlight = Number.isInteger(previousStep.row) && Number.isInteger(previousStep.col)
+            ? {
+                row: previousStep.row,
+                col: previousStep.col,
+                type: "solution"
+            }
+            : null;
+    } else {
+        currentSolverHighlight = null;
+    }
+
+    setSolverMessage(step.message || DEFAULT_SOLVER_MESSAGE);
+    drawBoard();
+    updateSolverControls();
+}
+
+function advanceSolverStep() {
+    if (!hasPreparedSolverTrace() || hasCompletedSolverTrace()) {
+        stopSolverPlayback(false);
+        updateSolverControls();
+        return false;
+    }
+
+    solverStepIndex += 1;
+    applySolverStep(solverSteps[solverStepIndex]);
+
+    if (hasCompletedSolverTrace()) {
+        stopSolverPlayback(false);
+        setStatus(`Loesung fuer ${boardSize} x ${boardSize} Schritt fuer Schritt aufgebaut.`, "green");
+        updateSolverControls();
+    }
+
+    return true;
+}
+
+function scheduleNextSolverPlaybackStep() {
+    stopSolverPlayback(false);
+
+    solverTimerId = window.setTimeout(() => {
+        solverTimerId = null;
+
+        const advanced = advanceSolverStep();
+
+        if (advanced && !hasCompletedSolverTrace()) {
+            scheduleNextSolverPlaybackStep();
+            return;
+        }
+
+        updateSolverControls();
+    }, solverSpeedMs);
+
+    updateSolverControls();
+}
+
+function startSolverPlayback(stepImmediately = true) {
+    if (!hasPreparedSolverTrace() || hasCompletedSolverTrace()) {
+        updateSolverControls();
+        return;
+    }
+
+    if (stepImmediately) {
+        const advanced = advanceSolverStep();
+
+        if (!advanced || hasCompletedSolverTrace()) {
+            updateSolverControls();
+            return;
+        }
+    }
+
+    scheduleNextSolverPlaybackStep();
+}
+
+async function prepareSolutionTrace() {
+    const endpoint = mode === "rooks" ? "/solve_rooks_trace" : "/solve_trace";
+    const requestId = ++solverRequestId;
+
+    solverLoading = true;
+    stopSolverPlayback(false);
+    solverSteps = [];
+    solverStepIndex = -1;
+    currentSolverHighlight = null;
+    setSolverMessage(`Berechne ${getPieceLabel(mode)}-Ablauf fuer ${boardSize} x ${boardSize}...`);
+    setStatus(`Solver berechnet die Schritte fuer ${boardSize} x ${boardSize}.`, "#2563eb");
+    updateSolverControls();
+
+    try {
+        const response = await fetch(`${endpoint}?size=${boardSize}`);
+
+        if (!response.ok) {
+            throw new Error("trace request failed");
+        }
+
+        const trace = await response.json();
+
+        if (requestId !== solverRequestId) {
+            return false;
+        }
+
+        solverSteps = Array.isArray(trace.steps) ? trace.steps : [];
+        solverStepIndex = -1;
+        board = Array.isArray(trace.initial_board) ? trace.initial_board.slice() : createEmptyBoard(boardSize);
+        currentSolverHighlight = null;
+
+        if (!trace.solved || solverSteps.length === 0) {
+            setSolverMessage("Keine Loesung gefunden.");
+            setStatus("Keine Loesung fuer dieses Brett gefunden.", "red");
+            drawBoard();
+            return false;
+        }
+
+        setSolverMessage(
+            mode === "queens"
+                ? `Ablauf bereit mit ${solverSteps.length} Schritten. Nutze Next Step oder Play Animation, um das Backtracking zu verfolgen.`
+                : `Ablauf bereit mit ${solverSteps.length} Schritten. Nutze Next Step oder starte die Animation.`
+        );
+        setStatus("Solver-Ablauf bereit. Nutze Next Step oder Play Animation.", "#2563eb");
+        drawBoard();
+        return true;
+    } catch (error) {
+        if (requestId !== solverRequestId) {
+            return false;
+        }
+
+        setSolverMessage("Der Solver-Ablauf konnte nicht geladen werden.");
+        setStatus("Der Solver-Ablauf konnte nicht geladen werden.", "red");
+        return false;
+    } finally {
+        if (requestId === solverRequestId) {
+            solverLoading = false;
+            updateSolverControls();
         }
     }
 }
+
+async function nextSolverStep() {
+    if (solverLoading) {
+        return;
+    }
+
+    if (!hasPreparedSolverTrace()) {
+        const prepared = await prepareSolutionTrace();
+
+        if (!prepared) {
+            return;
+        }
+    }
+
+    if (isSolverPlaying()) {
+        stopSolverPlayback(false);
+    }
+
+    if (!advanceSolverStep()) {
+        setStatus("Der Solver-Ablauf ist bereits abgeschlossen.", "#2563eb");
+    }
+}
+
+async function toggleSolverPlayback() {
+    if (solverLoading) {
+        return;
+    }
+
+    if (isSolverPlaying()) {
+        stopSolverPlayback();
+        setStatus("Solver-Animation pausiert.", "#2563eb");
+        return;
+    }
+
+    if (!hasPreparedSolverTrace()) {
+        const prepared = await prepareSolutionTrace();
+
+        if (!prepared) {
+            return;
+        }
+    }
+
+    if (hasCompletedSolverTrace()) {
+        rewindSolverTrace();
+    }
+
+    setStatus("Solver-Animation laeuft.", "#2563eb");
+    startSolverPlayback(true);
+}
+
+async function solve() {
+    await prepareSolutionTrace();
+}
+
+async function instantSolve() {
+    if (solverLoading) {
+        return;
+    }
+
+    const endpoint = mode === "rooks" ? "/solve_rooks" : "/solve";
+    const requestId = ++solverRequestId;
+
+    solverLoading = true;
+    stopSolverPlayback(false);
+    solverSteps = [];
+    solverStepIndex = -1;
+    currentSolverHighlight = null;
+    setSolverMessage(`Lade sofortige ${getPieceLabel(mode)}-Loesung fuer ${boardSize} x ${boardSize}...`);
+    setStatus(`Sofortige Loesung wird geladen.`, "#2563eb");
+    updateSolverControls();
+
+    try {
+        const response = await fetch(`${endpoint}?size=${boardSize}`);
+
+        if (!response.ok) {
+            throw new Error("instant solve request failed");
+        }
+
+        const solution = await response.json();
+
+        if (requestId !== solverRequestId) {
+            return;
+        }
+
+        board = mode === "queens" && Array.isArray(solution[0]) ? solution[0].slice() : solution.slice();
+        currentSolverHighlight = null;
+        setSolverMessage("Sofortige Loesung geladen. Starte Solve Step-by-Step, wenn du den Ablauf sehen moechtest.");
+        setStatus(`Loesung fuer ${boardSize} x ${boardSize} sofort geladen.`, "green");
+        drawBoard();
+    } catch (error) {
+        if (requestId !== solverRequestId) {
+            return;
+        }
+
+        setSolverMessage("Die sofortige Loesung konnte nicht geladen werden.");
+        setStatus("Die sofortige Loesung konnte nicht geladen werden.", "red");
+    } finally {
+        if (requestId === solverRequestId) {
+            solverLoading = false;
+            updateSolverControls();
+        }
+    }
+}
+
+function resetBoard(options = {}) {
+    const {
+        statusMessageText = "",
+        statusColor = "",
+        solverMessageText = `${getPieceLabel(mode)}-Solver bereit. ${DEFAULT_SOLVER_MESSAGE}`
+    } = options;
+
+    discardSolverTrace(solverMessageText);
+    board = createEmptyBoard(boardSize);
+    currentSolverHighlight = null;
+
+    if (statusMessageText) {
+        setStatus(statusMessageText, statusColor);
+    } else {
+        setStatus();
+    }
+
+    drawBoard();
+}
+
+function updateQueenList() {
+    queenList.innerHTML = "";
+
+    let count = 1;
+
+    for (let row = 0; row < boardSize; row++) {
+        if (board[row] === EMPTY_CELL) {
+            continue;
+        }
+
+        const col = board[row];
+        const position = `${getColumnLabel(col)}${boardSize - row}`;
+        const li = document.createElement("li");
+
+        li.textContent = `${mode === "queens" ? "Dame" : "Turm"} ${count}: ${position}`;
+        queenList.appendChild(li);
+        count += 1;
+    }
+}
+
+async function saveGame() {
+    const response = await fetch("/save", {
+        method: "POST",
+        headers: {
+            "Content-Type": "application/json"
+        },
+        body: JSON.stringify({
+            board,
+            mode,
+            boardSize,
+            saveName: saveNameInput.value,
+            saveNote: saveNoteInput.value,
+            isFavorite: saveFavoriteInput.checked
+        })
+    });
+
+    if (!response.ok) {
+        setStatus("Der Speicherstand konnte nicht gespeichert werden.", "red");
+        return;
+    }
+
+    const data = await response.json();
+
+    toggleSavePanel(false);
+    await refreshSavePoints();
+    setStatus(`Speicherpunkt "${data.save_point.save_name}" gespeichert.`, "green");
+}
+
+async function loadGame() {
+    const response = await fetch("/load");
+    const data = await response.json();
+    applyLoadedGame(data);
+}
+
+async function loadSavePoint(savePointId) {
+    const response = await fetch(`/load/${savePointId}`);
+
+    if (!response.ok) {
+        setStatus("Dieser Speicherstand konnte nicht geladen werden.", "red");
+        return;
+    }
+
+    const data = await response.json();
+
+    applyLoadedGame(data);
+    setStatus(`Speicherpunkt "${data.save_name}" geladen.`, "green");
+    toggleSavePointsPanel(false);
+}
+
+async function toggleSavePointFavorite(savePointId) {
+    const response = await fetch(`/save_points/${savePointId}/favorite`, {
+        method: "POST"
+    });
+
+    if (!response.ok) {
+        setStatus("Favorit konnte nicht aktualisiert werden.", "red");
+        return;
+    }
+
+    await refreshSavePoints();
+    setStatus("Favoritenstatus aktualisiert.", "#2563eb");
+}
+
+async function deleteSavePoint(savePointId) {
+    const confirmed = window.confirm("Diesen Speicherpunkt wirklich loeschen?");
+
+    if (!confirmed) {
+        return;
+    }
+
+    const response = await fetch(`/save_points/${savePointId}`, {
+        method: "DELETE"
+    });
+
+    if (!response.ok) {
+        setStatus("Speicherpunkt konnte nicht geloescht werden.", "red");
+        return;
+    }
+
+    await refreshSavePoints();
+    setStatus("Speicherpunkt geloescht.", "#2563eb");
+}
+
+pendingBoardSize = boardSize;
+updateModeButtons();
+updateBoardSizeDisplays(boardSize);
+updateSolverSpeed(solverSpeedMs);
+setSolverMessage(`${getPieceLabel(mode)}-Solver bereit. ${DEFAULT_SOLVER_MESSAGE}`);
+updateSolverControls();
+drawBoard();

app/templates/dashboard.html

@@ -48,29 +48,146 @@
         <div class="mode-switch">
             <button class="btn active" onclick="setMode('queens')" id="btnQueens">♛ Damen</button>
             <button class="btn secondary" onclick="setMode('rooks')" id="btnRooks">♜ Türme</button>
+            <button class="btn secondary" onclick="toggleSidebar()" id="btnSidebar">Board Settings</button>
         </div>
 
 
         <!-- ♟️ Game Card -->
         <div class="card game-card">
-            <h2>♟️ 8-Damen Spiel</h2>
+            <h2>♟️ Damen- und Tuerme-Spiel</h2>
+            <p class="board-size-info">Aktuelle Brettgroesse: <span id="boardSizeValue">8</span> x <span
+                    id="boardSizeValueMirror">8</span></p>
 
             <p id="statusMessage"></p>
             <div class="board" id="board"></div>
 
+            <div class="solver-panel">
+                <div class="solver-panel-header">
+                    <div>
+                        <h3>Solver-Ablauf</h3>
+                        <p class="solver-message" id="solverMessage">Bereite einen Ablauf vor und spiele ihn Schritt fuer Schritt ab.</p>
+                    </div>
+                    <p class="solver-step-info" id="solverStepInfo">Schritt 0 / 0</p>
+                </div>
+
+                <div class="solver-controls">
+                    <button class="btn" onclick="prepareSolutionTrace()" id="btnPrepareSolve" type="button">Solve Step-by-Step</button>
+                    <button class="btn secondary" onclick="instantSolve()" id="btnInstantSolve" type="button">Instant Solve</button>
+                    <button class="btn secondary" onclick="nextSolverStep()" id="btnNextStep" type="button">Next Step</button>
+                    <button class="btn secondary" onclick="toggleSolverPlayback()" id="btnPlayPause" type="button">Play Animation</button>
+                </div>
+
+                <div class="solver-speed">
+                    <label class="solver-speed-label" for="solverSpeedInput">Speed</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>
+            </div>
+
             <div class="controls">
-                <button class="btn" onclick="solve()">Solve</button>
                 <button class="btn" onclick="checkSolution()">Check</button>
                 <button class="btn secondary" onclick="resetBoard()">Reset</button>
+
+                <button class="btn" onclick="openSavePanel()">💾 Save</button>
+                <button class="btn" onclick="openSavePointsPanel()">📂 Load</button>
             </div>
         </div>
 
         <div class="card">
-            <h3>📋 Damen Positionen</h3>
+            <h3>📋 Figuren Positionen</h3>
             <ul id="queenList"></ul>
         </div>
     </div>
 
+    <aside class="sidebar" id="settingsSidebar" aria-hidden="true">
+        <div class="sidebar-header">
+            <h3>Brettgroesse</h3>
+            <button class="btn secondary sidebar-close" onclick="toggleSidebar(false)" type="button">Schliessen</button>
+        </div>
+
+        <p>Wähle eine Grösse zwischen 4 und 13.</p>
+
+        <label class="sidebar-label" for="boardSizeInput">Groesse</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()" type="button">Apply Size</button>
+        <p class="sidebar-hint">Das Brett wird beim Ändern zur Sicherheit zurückgesetzt.</p>
+    </aside>
+
+    <aside class="sidebar save-sidebar" id="saveSidebar" aria-hidden="true">
+        <div class="sidebar-header">
+            <h3>Speicherpunkt</h3>
+            <button class="btn secondary sidebar-close" onclick="toggleSavePanel(false)" type="button">Schliessen</button>
+        </div>
+
+        <p>Gib dem Spielstand einen klaren Namen und optional eine kurze Notiz.</p>
+
+        <label class="sidebar-label" for="saveNameInput">Name</label>
+        <input class="sidebar-input" id="saveNameInput" type="text" maxlength="80" placeholder="z. B. Fast geloeste Dame 8x8">
+
+        <label class="sidebar-label" for="saveNoteInput">Notiz</label>
+        <textarea class="sidebar-input sidebar-textarea" id="saveNoteInput" rows="4" maxlength="240"
+            placeholder="z. B. Gute Startposition fuer Tuermetest"></textarea>
+
+        <label class="sidebar-checkbox">
+            <input id="saveFavoriteInput" type="checkbox">
+            Als Favorit markieren
+        </label>
+
+        <button class="btn" onclick="saveGame()" type="button">Jetzt speichern</button>
+    </aside>
+
+    <aside class="sidebar save-points-sidebar" id="savePointsSidebar" aria-hidden="true">
+        <div class="sidebar-header">
+            <h3>Save Points</h3>
+            <button class="btn secondary sidebar-close" onclick="toggleSavePointsPanel(false)" type="button">Schliessen</button>
+        </div>
+
+        <p>Waehle einen Speicherstand aus der Liste.</p>
+
+        <div class="save-point-filters">
+            <label class="sidebar-label" for="savePointModeFilter">Modus</label>
+            <select class="sidebar-input" id="savePointModeFilter" onchange="refreshSavePoints()">
+                <option value="all">Alle</option>
+                <option value="queens">Damen</option>
+                <option value="rooks">Tuerme</option>
+            </select>
+
+            <label class="sidebar-label" for="savePointSizeFilter">Brettgroesse</label>
+            <select class="sidebar-input" id="savePointSizeFilter" onchange="refreshSavePoints()">
+                <option value="all">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" for="savePointSortFilter">Sortierung</label>
+            <select class="sidebar-input" id="savePointSortFilter" onchange="refreshSavePoints()">
+                <option value="newest">Neueste zuerst</option>
+                <option value="oldest">Aelteste zuerst</option>
+                <option value="updated">Zuletzt bearbeitet</option>
+                <option value="favorites">Favoriten zuerst</option>
+            </select>
+
+            <label class="sidebar-checkbox">
+                <input id="savePointFavoritesOnly" type="checkbox" onchange="refreshSavePoints()">
+                Nur Favoriten anzeigen
+            </label>
+        </div>
+
+        <div class="save-points-list" id="savePointsList">
+            <p class="sidebar-hint">Noch keine Speicherstaende gefunden.</p>
+        </div>
+    </aside>
+
+    <div class="sidebar-backdrop" id="sidebarBackdrop" onclick="toggleSidebar(false)"></div>
+    <div class="sidebar-backdrop" id="saveBackdrop" onclick="toggleSavePanel(false)"></div>
+    <div class="sidebar-backdrop" id="savePointsBackdrop" onclick="toggleSavePointsPanel(false)"></div>
+
     <script src="../static/js/dashboard.js"></script>
 
 </body>

database_setup.sql

@@ -5,3 +5,16 @@ CREATE TABLE users (
     email VARCHAR(120) NOT NULL UNIQUE,
     created_at DATETIME DEFAULT CURRENT_TIMESTAMP
 );
+
+CREATE TABLE game_state (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    user_id INTEGER NOT NULL,
+    board TEXT NOT NULL,             -- JSON String (z.B. "[0,4,7,5,2,6,1,3]")
+    mode TEXT NOT NULL,              -- "queens" oder "rooks"
+    board_size INTEGER NOT NULL DEFAULT 8,
+    save_name VARCHAR(80) NOT NULL DEFAULT 'Unnamed Save',
+    save_note TEXT NOT NULL DEFAULT '',
+    is_favorite BOOLEAN NOT NULL DEFAULT 0,
+    created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
+    updated_at DATETIME DEFAULT CURRENT_TIMESTAMP
+);