I have a SaaS deployed that does just that. Choose a back-end that includes easy handling of POST requests (Php, Django, Elixir-Phoenix) and ignore all the Jav

I have a SaaS deployed that does just that. Choose a back-end that includes easy handling of POST requests (Php, Django, Elixir-Phoenix) and ignore all the Javascript garbage they peddle on top. You don't need a CSS framework or a language that compiles to CSS, you can recreate most modern responsive web-apps with 500 lines of pure CSS and a good understanding of the flex property. You don't even need Javascript if all you want is simple forms.