“ This demo is optimized for desktop screens (1000px+).”

Opportunity missed with me, not everyone browses HN on their desktop.

At least have some screenshots of your app so I am motivated to check later.

I think especially for websites / web apps you'd want to start with a "mobile first" design, as is common in web design.

It's almost always easier to go from lower widths to large widths than the other way around for good responsive designs. This, and 1000px being an arbitrary number, doesn't give me confidence.

It works when I rotate the phone

Same here.