Typography.
Three faces, three jobs: serif is the voice, sans is the work, mono is the evidence. A reader should know what kind of sentence they're in before they read it.
The faces
serif — Georgia, Cambria, "Times New Roman", Times, serif
sans — -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif
mono — ui-monospace, SFMono-Regular, Menlo, Consolas, monospace
All three are system font families: no webfonts, no licenses, no layout shift, and the site renders in native quality on every platform. Do not add a webfont without amending this page first.
The scale
Display.
Page title
Section heading
Subsection
Body text trusts the reader: contractions, concrete nouns, paragraphs that end on details.
Captions and supporting notes sit one step down in size and ink.
labels · file paths · chart annotations
Rules
Serif never does chrome.
No serif buttons, nav items, or form labels. If it functions, it’s sans.
Mono means verifiable.
Numbers in tables, file paths, code, tokens. If a reader could check it, set it in mono.
Two weights are enough.
Regular and semibold. Bold-everything is the typographic equivalent of shouting.
Punctuation on a budget.
At most one em dash per ~500 words; the orange full stop belongs to the wordmark, not to body text.