- The hidden fourth font: Tailwind's font-mono/font-sans utilities fall to
the SYSTEM stacks (SFMono/Menlo — a font the app never chose), and
streamdown's code-block chrome, mermaid-error, and the demo-card meta
all use them — so every teaching-prose code block rendered in the
system mono. Fixed at the token level: @theme now aliases --font-mono →
JetBrains Mono and --font-sans → Source Sans 3, so every utility use
resolves to the app's three fonts (chrome=JetBrains, prose=Source Sans,
display=CMU bold).
- Session titles: Source Sans 3 (the human-words voice — the same font
the words were typed in; mono = machine data stays on the meta line).
One rule, finally applied to the picker too. CMU bold titles are the
queued experiment if this reads wrong live.
Gates: typecheck, lint, 469/469. Live: title "Source Sans 3" 12.5px,
meta "JetBrains Mono" 11px; code blocks now JetBrains.