I'm creating an exceptionally difficult challenge that combines:
1. Complex nested structures with mixed brackets and quotes requiring precise balance matching
2. Unicode characters including zero-width spaces and RTL markers
3. Advanced email formats with quoted parts and IPv6 addresses
4. Mathematical expressions with Unicode superscripts/subscripts
5. Timestamps with different timezone formats and precisions
6. JSON-like structures with escaped quotes and nested elements 
7. XML-like tags wit... (truncated)