public function resetPassword($token, $newPassword)
    {
        // Check if the token is valid and not expired
        $sql = 'SELECT * FROM users WHERE reset_token = :token AND reset_token_expiry > NOW()';
        $stmt = $this->pdo->prepare($sql);
        $stmt->bindParam(':token', $token);
        $stmt->execute();
        $user = $stmt->fetch();

        if ($user) {
            // Update the password and clear the reset token
            $hashedPassword = password_hash($newPassword, PASSWORD_BCRYPT);
            $sql = 'UPDATE users SET password = :password, reset_token = NULL, reset_token_expiry = NULL WHERE id = :id';
            $stmt = $this->pdo->prepare($sql);
            $stmt->bindParam(':password', $hashedPassword);
            $stmt->bindParam(':id', $user['id']);
            $stmt->execute();

            return 'Your password has been reset successfully.';
        }
        return 'Invalid or expired token.';
    }