Typography

Human uses a dual-typeface system: Avenir for interface text and Geist Mono for code. The type scale follows a modular progression optimized for readability at every size.

Typefaces

Avenir (UI Text)

Avenir Next is the primary typeface across all surfaces — web, iOS, Android, and documentation. It provides clean, geometric letterforms with excellent readability at small sizes.

Font stack: 'Avenir Next', 'Avenir', system-ui, -apple-system, sans-serif

Geist Mono (Code)

Geist Mono is used for code blocks, terminal output, and monospaced content. It features programming ligatures and clear distinction between similar characters (0/O, 1/l/I).

Font stack: 'Geist Mono', 'SF Mono', 'Fira Code', 'Cascadia Code', monospace

Type Scale

Token	Size	Line Height	Weight	Usage
`text.xs`	12px (0.75rem)	1.5	400	Captions, badges, metadata
`text.sm`	14px (0.875rem)	1.5	400	Secondary text, table cells
`text.base`	16px (1rem)	1.6	400	Body text, form inputs
`text.lg`	18px (1.125rem)	1.5	500	Subtitles, emphasized body
`text.xl`	20px (1.25rem)	1.4	600	Card titles, section headers
`text.2xl`	24px (1.5rem)	1.3	600	Page section titles
`text.3xl`	30px (1.875rem)	1.25	700	Page titles
`text.4xl`	36px (2.25rem)	1.2	700	Hero subtitles
`text.5xl`	48px (3rem)	1.1	700	Hero headlines

Font Weights

Token	Value	Usage
`weight.regular`	400	Body text, descriptions
`weight.medium`	500	Emphasized body, labels
`weight.semibold`	600	Titles, buttons, nav items
`weight.bold`	700	Headlines, strong emphasis

Letter Spacing (Tracking)

Token	Value	Usage
`tracking.tight`	`-0.025em`	Headlines, display text
`tracking.normal`	`0em`	Body text
`tracking.wide`	`0.05em`	All-caps labels, badges

Usage Roles

Headings

h1 {
  font-size: var(--hu-text-3xl);
  font-weight: var(--hu-weight-bold);
  letter-spacing: var(--hu-tracking-tight);
}
h2 {
  font-size: var(--hu-text-2xl);
  font-weight: var(--hu-weight-semibold);
}
h3 {
  font-size: var(--hu-text-xl);
  font-weight: var(--hu-weight-semibold);
}

Body

p {
  font-size: var(--hu-text-base);
  line-height: 1.6;
  color: var(--hu-text);
}
.secondary {
  font-size: var(--hu-text-sm);
  color: var(--hu-text-muted);
}

Code

code {
  font-family: var(--hu-font-mono);
  font-size: var(--hu-text-sm);
}
pre code {
  font-size: var(--hu-text-xs);
  line-height: 1.6;
}

Cross-Platform Mapping

CSS Variable	Swift	Kotlin	C
`--hu-text-base`	`HUTokens.textBase`	`HUTokens.textBase`	N/A (terminal)
`--hu-weight-semibold`	`.semibold`	`FontWeight.SemiBold`	`HU_COLOR_BOLD`
`--hu-font-mono`	`Font.custom("GeistMono", ...)`	`FontFamily.Monospace`	N/A

Accessibility

Minimum body text size is 16px (1rem) for comfortable reading
Line heights are tuned per size — larger text uses tighter leading
letter-spacing: var(--hu-tracking-wide) is applied to all-caps text for legibility
Font weight never drops below 400 for body text