Surgical Fixes to HTML without Regeneration

Hi - full disclaimer, not a developer, very little coding knowledge. I asked Claude (not Claude Code) to generate one single interactive html web-page, that I open locally on my browser.

When I asked Claude to make small changes, each time it went and re-generated the whole, burning usage limits fast. I am on Pro plan.

Instead, what is the best way to do surgical changes without wasting token on re-generating the whole page again? Should I leverage projects, if so - how? Should I use Claude Code? Any suggestions would help!