/**
 * Centralized z-index scale for full-window chrome overlays (G2 — UI rework).
 *
 * In-cell veils/portals keep their historical low values (chrome 2–5, F3 z-20,
 * write-portal z-4, resume z-5); this scale is for floating windows and menus
 * mounted at the **chrome level** (ProjectsView/App), never inside
 * LayoutGrid/LeafView (G5).
 *
 * Consumers: `FloatingWindow` (floatingWindow), `MenuBar` dropdowns
 * (menuDropdown), `TicketPicker` (floatingWindowNested), background-task toasts
 * (toast). Introduced by lot B (#18) and adopted as the canonical scale by lot A
 * (#16). See the sprint scoping note `ui-rework-sprint-scoping-contracts`.
 */
export const zIndex = {
  /** Dropdown menus / popovers anchored to a control. */
  menuDropdown: 40,
  /** A top-level floating window (movable panel, editor overlay). */
  floatingWindow: 50,
  /** A floating window opened from within another floating window (e.g. a
   *  ticket picker launched from a sprint/link dialog). Sits above it. */
  floatingWindowNested: 60,
  /** Transient toasts, always on top. */
  toast: 70,
} as const;

/** A level name in the {@link zIndex} scale. */
export type ZIndexLevel = keyof typeof zIndex;