// THE SURFACE GAP (the marks spec) between touching BARS: the segments of a
// stacked bar are parted by a 2 px gap in the colour behind the plot, never by
// a line drawn around them. `--chart-gap` is that colour (tokens.css: the
// chart surface, and the reader's Canvas in forced colours). Recharts draws in
// CSS pixels, so a width here is a width on screen. A segment's stroke is
// centred on its edge: 1 px inside each of two touching segments makes the
// 2 px gap (the outer edges meet the surface, so nothing shows there).
//
// Stacked AREAS keep their series-coloured top edge (ruled after review,
// 2026-09-28): a surface stroke along a band's top also runs along the stack's
// upper edge and over any band under ~2 px, and on translucent fills it erased
// small values and cut peaks. A gap there waits on opaque fills (a ruling), a
// gap on inner boundaries only, and the growth chart's thin-band rule.
export const BAR_GAP = { stroke: "var(--chart-gap)", strokeWidth: 2 } as const;