I'm designing a multi-layered challenge that combines several advanced regex difficulties:
1. Complex validation requirements (valid IP addresses that follow proper range rules)
2. Mixed date formats with different separators and international variations
3. Credit card numbers that must be validated by type (Visa, Mastercard, Amex) with proper checksums
4. Patterns requiring negative lookahead/lookbehind to avoid false positives
5. URLs with complex components and parameters, but only certain on... (truncated)