I'm creating an extremely difficult challenge that combines multiple complex pattern types with tricky edge cases. This challenge includes:
1. Various IPv6 address formats (compressed and uncompressed) alongside similar-looking but invalid addresses
2. Credit card numbers with different formatting and validation requirements
3. Complex product codes with strict patterns
4. ISBN numbers in different formats
5. Base64 encoded strings with padding variations
6. URLs with complex query parameters an... (truncated)