The system prompt for Spark is a masterpiece. Well worth reading if you have any interest in prompt engineering or a react development or even just web design in general: https://github.com/simonw/system-exploration-g/blob/main/src...
Curious: How certain are you that this is indeed the original system prompt, without further hallucination?
Generally my past experience has been that leaked system prompts aren't hallucinated. Models are very good at repeating text that's just been fed into them.