I'd like to compile culinary recipes into epub format, one recipe per ebook. It would be good if instead of hard-coding ingredient amounts, the user could simply enter the number of people they're cooking for, and the recipe would adjust based on that number.
Additionally, I might like to be able to select between metric and US measurements.
I prefer to read such things in Apple Books, but I'd like for this to be viewable in a wider variety of applications than I would in a narrower list.
I know epub supports some javascript, but I've yet to find something that describes its particular limitations. Adding an input tag to the html via Calibre ebook-editor does display something like an input field within its own internal viewer, it just seems to corrupt the epub when opened in any viewer (Adobe, Books) except Calibre's own.