I'm creating an extraordinarily difficult challenge that combines:
1. Heavily nested structures with mixed brackets/quotes requiring precise balance
2. Complex Unicode patterns including zero-width characters and bidirectional text
3. Similar-looking patterns that require precise differentiation
4. Strings requiring careful escaping of metacharacters
5. Multiple date/time formats with fractional seconds and timezone offsets
6. Mathematical expressions with special symbols
7. Patterns that look s... (truncated)