I'm creating an extremely difficult challenge that combines multiple advanced regex patterns. The text sample includes complex emails with multiple subdomains and special characters, properly formatted international phone numbers, dates in ISO, European and US formats, IPv4 and IPv6 addresses, a UUID, a base64 encoded string, a HTML element with escaped attributes, a complex regex pattern that employs negative lookahead and backreferences, and a function declaration with nested structures. Addit... (truncated)