the three surfaces, resting and hovered

--color-bg-base

rest

white · neutral-900

hover

white + neutral-950/2.5 · neutral-900 + white/5

--color-bg-base-secondary

rest

neutral-50 · neutral-950

hover

neutral-50 + neutral-950/5 · neutral-950 + white/5

--color-bg-base-tertiary

rest

neutral-100 · neutral-800

hover

neutral-100 + neutral-950/5 · neutral-800 + white/5