I'm designing an extremely difficult challenge that combines multiple complex pattern types with subtle variations and edge cases. This includes: 1) Complex emails with unusual formats and quoted sections, 2) URLs with intricate query parameters and fragments, 3) Nested JSON-like structures requiring careful escaping, 4) Various date/time formats with different separators, 5) Identifiers that follow specific patterns but have subtle variations, 6) Phone numbers with country codes and extensions ... (truncated)