Learn the basics of WordPress first then check out Bricks Builder. It's not free but the best in it's class. If you aren't doing this professionally you'll experience a steep learning curve but once you master it, you can build pretty much anything you want extremely fast.
If you really want to build it in HTML and CSS you'd have to build your own theme.
So basically you think that I'm obligated to spend my money and time for the rest of my life to provide you a free service once I've started one. People like you are the reason why instances like lemm.ee shut down. Expecting the best service for nothing and be the loudest when something you don't like happens.
It's not just native Apps. Alternative web UIs like Thunder, Photon and Voyager need them too.