When I was learning webdev in the 2000s you could view source and copy paste pretty much anything. Learning by emulating is perfectly normal part of the process.
ChatGPT does NOT recommend using Mac IE 5.5
My mind was completely blanking on the methods/terms we used “back in the day” to target Mac IE 5.5 with CSS overrides and I even struck out on DuckDuckGo so I asked ChatGPT 4. In addition to giving me the answer I was looking for and code examples, it also first spent several paragraphs first telling me how ancient that browser and what a terrible idea it was to even try to support it.
And then closing with reiterating AGAIN how “strongly it recommended not targeting such an old browser” and told me to convince users to upgrade to Chrome, Safari, or Firefox. ?