class OzonAPIError(Exception):
    """Base exception for all Ozon API errors."""
    pass

class OzonAuthError(OzonAPIError):
    """Raised when authentication fails (e.g. invalid Client-Id or Api-Key)."""
    pass

class OzonRateLimitError(OzonAPIError):
    """Raised when API rate limits are exceeded (HTTP 429)."""
    pass

class OzonBadRequestError(OzonAPIError):
    """Raised when API returns HTTP 400 (Bad Request)."""
    pass