This challenge includes extremely advanced items covering multiple tricky aspects of regex pattern matching: nested brackets, advanced escaping, negative lookbehind/lookahead, deeply nested JSON within HTML attributes, multiple date/time formats, phone numbers with parentheses, different path styles for Windows vs. Unix, IP addresses in both IPv4 and IPv6 forms, recursion illusions, and backreferences. A single regex must handle all sorts of intricacies, including lookarounds and precise escapin... (truncated)