Components
Tabs
Pill tabs drawn by ::before (no track), underline tabs and route NavigationTabs, manual activation, scroll pager and collapse-to-menu overflow modes.
Pill (default)
28px (32 touch), padding 12, 14/20 w435, every tab in primary ink; hover = ghost pill (7.5 % / 5 %); active = the selected pill (15 % / 10 %, radius 8, inset 1px, flush at the outer edges). Arrow keys move focus only; Enter / Space select (manual activation).
Underline and route tabs
28px, primary ink, a 2px fill-primary underline (#191919 | #efefef) on a 1px list rule (4 % | 8 %). The label sits on an invisible active-weight copy so the active weight never changes the item width. NavigationTabs are links with aria-current (natural Tab order, no tablist).
Overflow
menu: when the tabs do not fit, they collapse into a 28px secondary trigger reading the active tab; the menu lists them as radios. scroll: a masked strip with a 28px “Scroll forward” pager that pages by one width.