Constant OVERLAY_LIFT 

pub const OVERLAY_LIFT: f32 = 1.5; // 1.5f32

How many surface steps the armed row of a menu stands off its panel.

A selected row is a lift (docs/design-language.md, “No brand accent”; HIG §9.3). On a floating panel one step measured ΔL* ≈ 11 and read as “no highlighting” on a dark desktop, so a panel takes a stronger lift step: half a step more, which clears ΔL* 15 on every material (tests/menu_highlight_render.rs) while staying a quiet grey on white, like the sidebar lift.