Design guidelines
Design the 390px screen first
Most visitors arrive on a phone. A page that is good at 390px is easy to make good at 1440px, not the reverse.
2 min read
Start with one column and a thumb. Rules that hold up:
- tap targets 44px or more, with space between them,
- primary actions in the lower half of the screen where a thumb rests,
- no horizontal scroll, ever; check long words and tables,
- heavy effects (video, WebGL) start only when on screen and stop when they leave,
- test with the keyboard open and with large system text.
Take a screenshot at 390px of every page before you call it done.