Components
Prose
Long-form reply text: the cds .prose rules with the reply font, text inset / stop, tables and the streaming word fade.
Assistant reply
v2 reply: serif 15/21 (Source Serif 4), flow .75em = 11.25px. Inside an assistant Message, p / headings get the 4px start inset and the 56px end stop (at a 736px column). Headings in the header weight (serif 520); strong 501; lists 30px start, primary markers; inline code 13.5 mono in primary ink on a 5 % | 7.5 % wash, no border, radius 4; tables open and borderless (message-line rules, 1.5em column gap, rows 37), inset 4px.
Fonts, size, spacing
font="response" is serif by default (V2-3: Source Serif 4, one --font-serif-face token); data-response-font="sans" on an ancestor opts out to sans. size="inherit" takes the surrounding size (thinking text, 14/21); spacing="lg" widens the block flow to 1em.
Response face
The quick brown fox jumps over the lazy dog.
Response face
The quick brown fox jumps over the lazy dog.
Thinking text inherits the 14px body size with a 1.5 line height.
Second paragraph.
Paragraph one.
Paragraph two, 1em below.
Compact density reply text is 14/20.
Streaming
While streaming, the renderer wraps appended words in span.prose-word; each fades in over 400 ms (none with reduced motion).