Typography
Serif headings, system sans for the interface, PingFang and system fonts for all Chinese text.
Thoughtful by design 温润而克制
Interface and body text use the system sans: SF Pro + PingFang on macOS and iOS, Segoe UI + Microsoft YaHei on Windows. The quick brown fox jumps over the lazy dog.
| Role | Font | Weight |
|---|---|---|
| Greeting display | Source Serif 4 | 330 |
| Page title | Source Serif 4 | 500 |
| Section heading | Source Serif 4 | 600 |
| Interface, body | -apple-system / Segoe UI / Roboto | 400 |
| Buttons, links, tags | same | 470 |
| Bold | same | 700 |
| Chinese (all roles) | PingFang SC → Hiragino Sans GB → Microsoft YaHei → Noto Sans CJK | same |
| Code | ui-monospace / SF Mono / Consolas | 400 |
Claude's own Anthropic Sans and Serif derive from the commercial Styrene and Tiempos, so MioUI does not use them. Source Serif 4 downloads only the Latin glyphs a page uses; no web font is loaded for Chinese.
Dark mode thinning
White text on dark backgrounds reads heavier, so dark mode thins every weight: 400→360, 470→460, 500→460, 600→560, 700→660.