iOS typography and dark mode

Good type is spacing and hierarchy, not a new font. Prefer SF Pro / system text styles. Apply ios-senior-ui-polish.

Type

Use text styles (largeTitle, title2, headline, body, subheadline, caption) so Dynamic Type works
Two weights on a screen (regular + semibold/semibold). Skip ultra-thin
3–4 sizes on a card, not six. Two close sizes read as a mistake — merge them
Line height shrinks as type grows. Titles are tight; captions need air
A heading belongs to the text below: more space above than below (about 3–4× vs 1×)
Line length: body is not full-bleed on iPad; keep a readable measure
primary for body, secondary for support. Pure black is loud; washed grey is unreadable
Tabular / monospaced digits for money, timers, stats: .monospacedDigit()
No orphans on large titles if you control breaks; don’t ship 56pt marketing headlines on iPhone
Sentence case. Tighten tracking slightly on large titles if custom