// Surrender game
    surrenderGame() {
        if (!this.isMultiplayer || !this.currentGameId) {
            this.showMessage('No active game to surrender', 'error');
            return;
        }
        
        this.socket.emit('surrender', { gameId: this.currentGameId });
    }
    
    // Handle rematch request from opponent
    handleRematchRequest(data) {
        const notification = document.createElement('div');
        notification.className = 'challenge-notification';
        notification.innerHTML = `
            <div class="challenge-content">
                <h3>Rematch Request!</h3>
                <p><strong>${data.from}</strong> wants a rematch</p>
                <p>Board size: ${data.boardSize}×${data.boardSize}</p>
                <div class="challenge-actions">
                    <button class="accept-btn" onclick="multiplayerClient.acceptRematch('${data.rematchId}')">
                        Accept
                    </button>
                    <button class="decline-btn" onclick="multiplayerClient.declineRematch('${data.rematchId}')">
                        Decline
                    </button>
               </div>
            </div>
        `;
        
        document.body.appendChild(notification);
        setTimeout(() => notification.classList.add('active'), 10);
    }
    
    // Send rematch request
    sendRematchRequest() {
        if (!this.opponentId) {
            this.showMessage('No opponent to challenge', 'error');
            return;
        }
        
        this.socket.emit('send_rematch', {
            opponentId: this.opponentId,
            boardSize: this.selectedBoardSize
        });
        
        this.showMessage(`Rematch request sent to ${this.opponent}`, 'info');
        document.getElementById('gameOverModal').classList.remove('active');
    }
    
    // Accept rematch
    acceptRematch(rematchId) {
        this.socket.emit('accept_rematch', { rematchId });
        
        // Hide game over modal
        document.getElementById('gameOverModal').classList.remove('active');
        
        // Remove notification
        const notifications = document.querySelectorAll('.challenge-notification');
        notifications.forEach(n => n.remove());
    }
    
    // Decline rematch
    declineRematch(rematchId) {
        this.socket.emit('decline_rematch', { rematchId });
        
        // Remove notification
        const notifications = document.querySelectorAll('.challenge-notification');
        notifications.forEach(n => n.remove());
    }