I wrote something very similar a few years ago – https://github.com/arp242/singlepage https://github.com/arp242/singlepage I mostly use it for a few Go program

I wrote something very similar a few years ago – https://github.com/arp242/singlepage https://github.com/arp242/singlepage I mostly use it for a few Go programs where I generate HTML; I can "just" use links to external stylesheets and JavaScript because that's more convenient to work with, and then process it to produce a single HTML file.