From his past experience with HTML/CSS, he can already make a page, has VSCode, knows how to use VSCode to commit & sync. The big thing this time was that he had to learn a lot of JS and had to get much more proficient with CSS.
So my guidance was more of a set of hints as needed, for example "you want to boxes side by side, figure out how to do that using CSS" .. then he'd go away and talk to Gemini and ultimately Gemini would give him multiple approaches that he could try.
When it came to animation, I explained that there are many ways to animate (CSS, JS, etc) and guided him towards animated images. Basically, we "chatted" about a feature, I gave him some hints, then he went off and talked to Gemini for syntax and wrote the code. Many features he knew exactly what to do. If he wasn't sure, he'd have a discussion with me.
Basically, I was like a senior dev sounding board. He was the junior developer doing the work. Gemini was his Google/StackOverflow.