Components
Artifact card
The artifact / file card under a reply: a flat 520 × 64 link-card row with an icon tile, title, meta and hover-revealed actions.
Artifact
v2 (V2-5 replaces the v1 sheet card): a link Card, max 520 × 64, radius 12, padding 16, gap 12. Icon tile 32 (radius 5.5, black / white 5 %, 20px secondary glyph); title 15/20 w435 primary is the card's link (its ::after covers the card) and toggles the panel (aria-pressed); meta 13/17 secondary. Fill #00000006 | #ffffff08 with one hover / pressed layer, no ring, no shadow. The ghost 28 actions appear on hover, keyboard focus, an open popup or busy, and always on touch.
Kinds and files
The kind only picks the glyph (no kind colours in v2). File cards use the same row (kind="file") with a ghost Download.