Mobile first — is a principle of starting design project work within a mobile version of website, instead of desktop web design creation.
It is probably obvious to everyone, even without analytics and research that the majority of internet users are on mobile devices.
Overview of mobile first and mandatory rules to create a good design within the principle.
- A tappable area should be no less than 44pt. Icons, inline text etc. — can be smaller, but the tappable area still 44pt.
- Minimal font-size 16px for all input fields. Doing font size smaller than 16px will make user experience bad, auto zooming webpage to input.
- Usability and accessibility are a must, not an option.
Ease life for yourself and your team: develop products with real or proto-content.