Mobile-first design means building your app or website for phones first, so it...

https://zulu-wiki.win/index.php/How_to_Write_Microcopy_for_Mobile_Forms_That_People_Actually_Finish

Mobile-first design means building your app or website for phones first, so it loads fast and feels easy to use. Buttons and menus are big enough to tap with your thumb, and pages are simple to move through