This kind of use case is where you’d use Alpine instead of HTMX (if you’re going for the no-build approach). It has everything you’d need for this, client-side

This kind of use case is where you’d use Alpine instead of HTMX (if you’re going for the no-build approach). It has everything you’d need for this, client-side store, etc. Alpine is basically light weight, no-build Vue. HTMX is really only about swapping out the elements on the page and pushing updates to the server, which in this case might just be lazy loading the calculator component that contains Alpine attributes and Tailwind elements, and HTMX only if there are elements to swap or you need to save state to the server.