class WBAPIError(Exception):
    """Base exception for all Wildberries API errors."""
    pass

class WBAuthError(WBAPIError):
    """Raised when authentication fails (HTTP 401)."""
    pass

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

class WBBadRequestError(WBAPIError):
    """Raised when API returns HTTP 400 (Bad Request)."""
    pass