The owner's repro: the appearance Bold color never applied anywhere.
Root cause: streamdown's default `strong` component renders bold as
<span class="font-semibold" data-streamdown="strong"> - NOT a
<strong> element - while the app's ink plumbing (.lh-prose
:where(strong, b) in globals.css, zero specificity by design) matches
strong/b ELEMENTS. So bold text never took --lh-ink-strong: not the
factory #c96b4a, not any settings boldColor (it rendered plain
foreground at weight 600). Italic always worked because streamdown
leaves `em` native - hence the asymmetry the owner noticed.
Fix: a `strong` override in mdComponents (the stable module-level set,
so Streamdown's memoized tree keeps identity) renders the semantic
element: <strong data-streamdown="strong">. Screen readers announce
emphasis again, the designed token rule applies unmodified, and the
weight reads 700 (the .lh-prose rule) instead of the span's 600.
Both Streamdown surfaces (MessageResponse, reasoning) pass
mdComponents, so every markdown surface is covered.
Verified live: bold in seedplan now renders #c96b4a at weight 700 in a
real <strong>; after PUTting boldColor #7dd3fc the live strong flips
to rgb(125,211,252) with no reload; italic unchanged (#6fa9d6 native
em). Scratch record restored to unset.
- src/core/math-delims.ts: pure preprocessing for the \(...\)/\[...\] math
contract — balanced delimiters rewrite to the two-dollar forms remark-math
parses ($ is never math). Skips code fences/spans, escaped delimiters, and
leaves unbalanced (mid-stream) delimiters untouched. Display math renders
as a block: mid-paragraph gets blank-line padding; indented (list items)
degrades to inline so list continuations don't half-parse.
- message.tsx: transform in the render path (children-memoized); math plugin
now singleDollarTextMath: false — the currency hazard dies structurally.
remark-breaks via the cjk remarkPluginsAfter slot (the bare remarkPlugins
prop would replace the [remark-gfm, codeMeta] defaults).
- mermaid: dark theme + sans font via Streamdown's mermaid prop; dark-styled
error fallback (components/mermaid-error.tsx) with error, source in
<details>, and retry.
- globals.css (appended): @source for streamdown dist — its internal UI
chrome (code blocks, mermaid containers, tables) was entirely unstyled
because Tailwind v4 never scans node_modules; --color-sidebar → card; wide
mermaid SVGs capped to the column; .katex-display scrolls.
- tests/render-markdown.test.tsx: 26 tests (transform unit + render). The
math describe block in render-cards.test.tsx is updated to the new
contract ($...$ now renders as literal text — pinned).
amosblomqvist