The accent is brass, from the key tag — not blue. Blue is reserved for status. Brass appears at most three times on a screen: primary button, focus ring, selected cell.
Any number that sits in a column is set in IBM Plex Mono with tabular figures. Never set a price in the body face.
Hover lightens one step (brass-600 → brass-500) in 80ms; press darkens. No scale transforms. Focus ring is brass, 2px, visible on keyboard focus.
36px row, micro-caps heads, paper-sunk stripes, numeric columns right-aligned in mono. Elevation is a hairline rule plus a 1px inner highlight — no soft shadow.