diff --git a/.dockerignore b/.dockerignore
new file mode 100644
index 0000000..a145a50
--- /dev/null
+++ b/.dockerignore
@@ -0,0 +1,56 @@
+# Dependencies
+node_modules
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# Build output
+.next
+out
+dist
+build
+
+# Testing
+coverage
+.nyc_output
+*.test.ts
+*.test.tsx
+*.spec.ts
+*.spec.tsx
+__tests__
+jest.config.ts
+jest.setup.ts
+
+# Development files
+.git
+.gitignore
+.env.local
+.env.development.local
+.env.test.local
+.env.production.local
+
+# IDE
+.vscode
+.idea
+*.swp
+*.swo
+*~
+
+# OS files
+.DS_Store
+Thumbs.db
+
+# Documentation
+README.md
+screenshots
+*.md
+
+# Docker
+Dockerfile
+.dockerignore
+docker-compose.yml
+
+# Misc
+.eslintrc.json
+.prettierrc
+.editorconfig
diff --git a/src/lib/i18n/translations.ts b/src/lib/i18n/translations.ts
new file mode 100644
index 0000000..8b94201
--- /dev/null
+++ b/src/lib/i18n/translations.ts
@@ -0,0 +1,433 @@
+export type SupportedLanguage = 'en' | 'de' | 'fr' | 'it';
+
+export interface Translations {
+    // Common
+    common: {
+        close: string;
+        cancel: string;
+        confirm: string;
+        loading: string;
+        error: string;
+    };
+
+    // Header
+    header: {
+        tagline: string;
+        buyMeABeer: string;
+        github: string;
+    };
+
+    // Start Screen
+    start: {
+        title: string;
+        settings: string;
+        language: string;
+        apiKey: string;
+        apiKeyPlaceholder: string;
+        getApiKey: string;
+        startGame: string;
+        resumeGame: string;
+        startNewGame: string;
+        chooseCoach: string;
+        importPosition: string;
+        importPositionPlaceholder: string;
+        apiKeyRequired: string;
+        colorSelection: string;
+        playAsWhite: string;
+        playAsBlack: string;
+        randomColor: string;
+    };
+
+    // Game
+    game: {
+        playingAs: string;
+        vs: string;
+        backToMenu: string;
+        stockfishStrength: string;
+        depth: string;
+        undoMove: string;
+        gameHistory: string;
+        analyze: string;
+        noMovesYet: string;
+        white: string;
+        black: string;
+    };
+
+    // Tutor
+    tutor: {
+        aiCoach: string;
+        askCoach: string;
+        hint: string;
+        bestMove: string;
+    };
+
+    // Game Over
+    gameOver: {
+        title: string;
+        checkmate: string;
+        youWon: string;
+        youLost: string;
+        draw: string;
+        stalemate: string;
+        mistakes: string;
+        aiSummary: string;
+        move: string;
+        evalBefore: string;
+        evalAfter: string;
+        bestMove: string;
+        newGame: string;
+    };
+
+    // Analysis
+    analysis: {
+        title: string;
+        currentPosition: string;
+        evaluation: string;
+        bestMove: string;
+        aiAnalysis: string;
+    };
+
+    // API Key Input
+    apiKeyInput: {
+        title: string;
+        description: string;
+        placeholder: string;
+        submit: string;
+        getKey: string;
+    };
+}
+
+const en: Translations = {
+    common: {
+        close: 'Close',
+        cancel: 'Cancel',
+        confirm: 'Confirm',
+        loading: 'Loading...',
+        error: 'Error',
+    },
+    header: {
+        tagline: 'with Gemini & Stockfish',
+        buyMeABeer: 'Buy Me a Beer',
+        github: 'GitHub',
+    },
+    start: {
+        title: 'Chess Tutor AI',
+        settings: '1. Settings',
+        language: 'Language',
+        apiKey: 'Google Gemini API Key',
+        apiKeyPlaceholder: 'AIzaSy...',
+        getApiKey: 'Get free key',
+        startGame: '2. Start Game',
+        resumeGame: 'Resume Previous Game',
+        startNewGame: 'Start New Game instead...',
+        chooseCoach: 'Choose Your Coach:',
+        importPosition: 'Import Position (Optional FEN)',
+        importPositionPlaceholder: 'rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1',
+        apiKeyRequired: 'Please enter a valid API Key to continue.',
+        colorSelection: 'Choose Your Color:',
+        playAsWhite: 'Play as White',
+        playAsBlack: 'Play as Black',
+        randomColor: 'Random',
+    },
+    game: {
+        playingAs: 'Playing as',
+        vs: 'vs',
+        backToMenu: '← Back to Menu',
+        stockfishStrength: 'Stockfish Strength',
+        depth: 'Depth',
+        undoMove: 'Undo Last Move',
+        gameHistory: 'Game History',
+        analyze: 'Analyze',
+        noMovesYet: 'No moves yet.',
+        white: 'White',
+        black: 'Black',
+    },
+    tutor: {
+        aiCoach: 'AI Coach',
+        askCoach: 'Ask your coach...',
+        hint: 'Hint',
+        bestMove: 'Best Move',
+    },
+    gameOver: {
+        title: 'Game Over',
+        checkmate: 'Checkmate!',
+        youWon: 'You won!',
+        youLost: 'You lost.',
+        draw: 'Draw!',
+        stalemate: 'Stalemate!',
+        mistakes: 'Your Mistakes',
+        aiSummary: 'AI Summary',
+        move: 'Move',
+        evalBefore: 'Eval Before',
+        evalAfter: 'Eval After',
+        bestMove: 'Best Move',
+        newGame: 'New Game',
+    },
+    analysis: {
+        title: 'Position Analysis',
+        currentPosition: 'Current Position',
+        evaluation: 'Evaluation',
+        bestMove: 'Best Move',
+        aiAnalysis: 'AI Analysis',
+    },
+    apiKeyInput: {
+        title: 'API Key Required',
+        description: 'Please enter your Google Gemini API key to continue.',
+        placeholder: 'Enter your API key...',
+        submit: 'Submit',
+        getKey: 'Get a free API key',
+    },
+};
+
+const de: Translations = {
+    common: {
+        close: 'Schließen',
+        cancel: 'Abbrechen',
+        confirm: 'Bestätigen',
+        loading: 'Lädt...',
+        error: 'Fehler',
+    },
+    header: {
+        tagline: 'mit Gemini & Stockfish',
+        buyMeABeer: 'Spendier mir ein Bier',
+        github: 'GitHub',
+    },
+    start: {
+        title: 'Chess Tutor AI',
+        settings: '1. Einstellungen',
+        language: 'Sprache',
+        apiKey: 'Google Gemini API-Schlüssel',
+        apiKeyPlaceholder: 'AIzaSy...',
+        getApiKey: 'Kostenlosen Schlüssel erhalten',
+        startGame: '2. Spiel starten',
+        resumeGame: 'Vorheriges Spiel fortsetzen',
+        startNewGame: 'Stattdessen neues Spiel starten...',
+        chooseCoach: 'Wähle deinen Trainer:',
+        importPosition: 'Position importieren (Optional FEN)',
+        importPositionPlaceholder: 'rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1',
+        apiKeyRequired: 'Bitte geben Sie einen gültigen API-Schlüssel ein, um fortzufahren.',
+        colorSelection: 'Wähle deine Farbe:',
+        playAsWhite: 'Als Weiß spielen',
+        playAsBlack: 'Als Schwarz spielen',
+        randomColor: 'Zufällig',
+    },
+    game: {
+        playingAs: 'Spielst als',
+        vs: 'gegen',
+        backToMenu: '← Zurück zum Menü',
+        stockfishStrength: 'Stockfish-Stärke',
+        depth: 'Tiefe',
+        undoMove: 'Letzten Zug rückgängig',
+        gameHistory: 'Spielverlauf',
+        analyze: 'Analysieren',
+        noMovesYet: 'Noch keine Züge.',
+        white: 'Weiß',
+        black: 'Schwarz',
+    },
+    tutor: {
+        aiCoach: 'KI-Trainer',
+        askCoach: 'Frage deinen Trainer...',
+        hint: 'Hinweis',
+        bestMove: 'Bester Zug',
+    },
+    gameOver: {
+        title: 'Spiel beendet',
+        checkmate: 'Schachmatt!',
+        youWon: 'Du hast gewonnen!',
+        youLost: 'Du hast verloren.',
+        draw: 'Remis!',
+        stalemate: 'Patt!',
+        mistakes: 'Deine Fehler',
+        aiSummary: 'KI-Zusammenfassung',
+        move: 'Zug',
+        evalBefore: 'Bewertung vorher',
+        evalAfter: 'Bewertung nachher',
+        bestMove: 'Bester Zug',
+        newGame: 'Neues Spiel',
+    },
+    analysis: {
+        title: 'Stellungsanalyse',
+        currentPosition: 'Aktuelle Stellung',
+        evaluation: 'Bewertung',
+        bestMove: 'Bester Zug',
+        aiAnalysis: 'KI-Analyse',
+    },
+    apiKeyInput: {
+        title: 'API-Schlüssel erforderlich',
+        description: 'Bitte geben Sie Ihren Google Gemini API-Schlüssel ein, um fortzufahren.',
+        placeholder: 'Geben Sie Ihren API-Schlüssel ein...',
+        submit: 'Absenden',
+        getKey: 'Kostenlosen API-Schlüssel erhalten',
+    },
+};
+
+const fr: Translations = {
+    common: {
+        close: 'Fermer',
+        cancel: 'Annuler',
+        confirm: 'Confirmer',
+        loading: 'Chargement...',
+        error: 'Erreur',
+    },
+    header: {
+        tagline: 'avec Gemini & Stockfish',
+        buyMeABeer: 'Offrez-moi une bière',
+        github: 'GitHub',
+    },
+    start: {
+        title: 'Chess Tutor AI',
+        settings: '1. Paramètres',
+        language: 'Langue',
+        apiKey: 'Clé API Google Gemini',
+        apiKeyPlaceholder: 'AIzaSy...',
+        getApiKey: 'Obtenir une clé gratuite',
+        startGame: '2. Démarrer la partie',
+        resumeGame: 'Reprendre la partie précédente',
+        startNewGame: 'Démarrer une nouvelle partie...',
+        chooseCoach: 'Choisissez votre coach :',
+        importPosition: 'Importer une position (FEN optionnel)',
+        importPositionPlaceholder: 'rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1',
+        apiKeyRequired: 'Veuillez entrer une clé API valide pour continuer.',
+        colorSelection: 'Choisissez votre couleur :',
+        playAsWhite: 'Jouer Blancs',
+        playAsBlack: 'Jouer Noirs',
+        randomColor: 'Aléatoire',
+    },
+    game: {
+        playingAs: 'Jouant',
+        vs: 'contre',
+        backToMenu: '← Retour au menu',
+        stockfishStrength: 'Force de Stockfish',
+        depth: 'Profondeur',
+        undoMove: 'Annuler le dernier coup',
+        gameHistory: 'Historique de la partie',
+        analyze: 'Analyser',
+        noMovesYet: 'Aucun coup pour le moment.',
+        white: 'Blancs',
+        black: 'Noirs',
+    },
+    tutor: {
+        aiCoach: 'Coach IA',
+        askCoach: 'Demandez à votre coach...',
+        hint: 'Indice',
+        bestMove: 'Meilleur coup',
+    },
+    gameOver: {
+        title: 'Partie terminée',
+        checkmate: 'Échec et mat !',
+        youWon: 'Vous avez gagné !',
+        youLost: 'Vous avez perdu.',
+        draw: 'Nulle !',
+        stalemate: 'Pat !',
+        mistakes: 'Vos erreurs',
+        aiSummary: 'Résumé IA',
+        move: 'Coup',
+        evalBefore: 'Éval. avant',
+        evalAfter: 'Éval. après',
+        bestMove: 'Meilleur coup',
+        newGame: 'Nouvelle partie',
+    },
+    analysis: {
+        title: 'Analyse de position',
+        currentPosition: 'Position actuelle',
+        evaluation: 'Évaluation',
+        bestMove: 'Meilleur coup',
+        aiAnalysis: 'Analyse IA',
+    },
+    apiKeyInput: {
+        title: 'Clé API requise',
+        description: 'Veuillez entrer votre clé API Google Gemini pour continuer.',
+        placeholder: 'Entrez votre clé API...',
+        submit: 'Soumettre',
+        getKey: 'Obtenir une clé API gratuite',
+    },
+};
+
+const it: Translations = {
+    common: {
+        close: 'Chiudi',
+        cancel: 'Annulla',
+        confirm: 'Conferma',
+        loading: 'Caricamento...',
+        error: 'Errore',
+    },
+    header: {
+        tagline: 'con Gemini & Stockfish',
+        buyMeABeer: 'Offrimi una birra',
+        github: 'GitHub',
+    },
+    start: {
+        title: 'Chess Tutor AI',
+        settings: '1. Impostazioni',
+        language: 'Lingua',
+        apiKey: 'Chiave API Google Gemini',
+        apiKeyPlaceholder: 'AIzaSy...',
+        getApiKey: 'Ottieni chiave gratuita',
+        startGame: '2. Inizia partita',
+        resumeGame: 'Riprendi partita precedente',
+        startNewGame: 'Inizia nuova partita...',
+        chooseCoach: 'Scegli il tuo allenatore:',
+        importPosition: 'Importa posizione (FEN opzionale)',
+        importPositionPlaceholder: 'rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1',
+        apiKeyRequired: 'Inserisci una chiave API valida per continuare.',
+        colorSelection: 'Scegli il tuo colore:',
+        playAsWhite: 'Gioca Bianco',
+        playAsBlack: 'Gioca Nero',
+        randomColor: 'Casuale',
+    },
+    game: {
+        playingAs: 'Giocando',
+        vs: 'contro',
+        backToMenu: '← Torna al menu',
+        stockfishStrength: 'Forza di Stockfish',
+        depth: 'Profondità',
+        undoMove: 'Annulla ultima mossa',
+        gameHistory: 'Cronologia partita',
+        analyze: 'Analizza',
+        noMovesYet: 'Nessuna mossa ancora.',
+        white: 'Bianco',
+        black: 'Nero',
+    },
+    tutor: {
+        aiCoach: 'Allenatore IA',
+        askCoach: 'Chiedi al tuo allenatore...',
+        hint: 'Suggerimento',
+        bestMove: 'Mossa migliore',
+    },
+    gameOver: {
+        title: 'Partita terminata',
+        checkmate: 'Scacco matto!',
+        youWon: 'Hai vinto!',
+        youLost: 'Hai perso.',
+        draw: 'Patta!',
+        stalemate: 'Stallo!',
+        mistakes: 'I tuoi errori',
+        aiSummary: 'Riepilogo IA',
+        move: 'Mossa',
+        evalBefore: 'Val. prima',
+        evalAfter: 'Val. dopo',
+        bestMove: 'Mossa migliore',
+        newGame: 'Nuova partita',
+    },
+    analysis: {
+        title: 'Analisi posizione',
+        currentPosition: 'Posizione attuale',
+        evaluation: 'Valutazione',
+        bestMove: 'Mossa migliore',
+        aiAnalysis: 'Analisi IA',
+    },
+    apiKeyInput: {
+        title: 'Chiave API richiesta',
+        description: 'Inserisci la tua chiave API Google Gemini per continuare.',
+        placeholder: 'Inserisci la tua chiave API...',
+        submit: 'Invia',
+        getKey: 'Ottieni chiave API gratuita',
+    },
+};
+
+export const translations: Record<SupportedLanguage, Translations> = {
+    en,
+    de,
+    fr,
+    it,
+};
diff --git a/src/lib/i18n/useTranslation.ts b/src/lib/i18n/useTranslation.ts
new file mode 100644
index 0000000..f52f784
--- /dev/null
+++ b/src/lib/i18n/useTranslation.ts
@@ -0,0 +1,17 @@
+import { SupportedLanguage, translations, Translations } from './translations';
+
+export function useTranslation(language: SupportedLanguage): Translations {
+    return translations[language] || translations.en;
+}
+
+export function getTranslation(language: SupportedLanguage, key: string): string {
+    const t = useTranslation(language);
+    const keys = key.split('.');
+    let value: any = t;
+
+    for (const k of keys) {
+        value = value?.[k];
+    }
+
+    return value || key;
+}