Here’s a quick summary of styles. See below for visual reference and more in-depth guidelines.
|17pt||Medium font weight|
iOS 10+ page titles are 34pt before scrolling, 17pt once scrolled
|Secondary text||15pt||Lighter color as well|
|13pt||Skip a font size between secondary and tertiary text|
|17pt||Highlight important buttons with medium font weight|
|Action Bar||10pt||Don't go smaller than this|
Let’s break this down element-by-element and look at illustrated examples. We’ll cover not just the actual font sizes, but also how Apple thinks about text styles.