/**

 * ============================================

 * Z-INDEX REGISTRY — Single source of truth (documentation layer; enforcement = use var(--z-*) from design-tokens.css only)

 * ============================================

 * Full architecture, problem list, and dev guidelines:

 *   docs/Z-INDEX-ARCHITECTURE.md

 *

 * All numeric z-index values live in design-tokens.css (:root --z-*).

 * This file documents the hierarchy only. Do NOT add literal z-index here.

 * Do NOT use magic numbers (e.g. 9999) in product CSS — use var(--z-*).

 *

 * Stacking order (bottom → top):

 *   --z-negative (-1) → --z-zero (0) → --z-base (1) → --z-content (10) → --z-content-above (50)

 *   → --z-content-top (100) → --z-filter-pills (1019) → --z-sticky / --z-sidebar (1020)

 *   → --z-mobile-cta (1025) / --z-navbar-overlay (1025) → --z-navbar (1030) → --z-sidebar-flyout (1032)

 *   → --z-cookie-banner / --z-mobile-action-bar (1035) → --z-offcanvas-backdrop (1040)

 *   → --z-guests-backdrop / --z-guests-selector (alias offcanvas 1040 / 1045) → --z-dropdown (1044) → --z-navbar-dropdown (1046) → --z-dropdown-teleported (1048)

 *   → --z-modal-backdrop (1050) → --z-modal (1055) → --z-modal-close (1060) → --z-modal-nested / --z-context-menu (1065)

 *   → --z-popover (1070) → --z-tooltip (1080) → --z-toast (1090)

 *   → --z-datepicker (1095) → --z-gallery (1100) → --z-lightbox (1105) → --z-skip-link (1110)
 *   → --z-google-places-autocomplete (10050) — Google .pac-container only (vendor DOM on body)

 *

 * Offcanvas / drawer: --z-offcanvas-backdrop (1040), --z-offcanvas / --z-drawer (1045).

 *

 * Admin shell: sidebar --z-admin-sidebar (1038), header --z-admin-header (1039), overlay --z-admin-sidebar-overlay (1037).
 * Dashboard: sidebar 1020, sidebar backdrop 1019, navbar 1030. Chat mobile drawer: --z-offcanvas-backdrop (1040) + --z-offcanvas (1045) for sidebar/backdrop (≤991.98px).

 * Mobile conflict guardrails:

 *   • body.modal-open / body.offcanvas-open / body.listing-detail-booking-open => hide bottom fixed bars (CTA/cookie/support FAB)

 *   • body.auth-modal-open => hide bottom fixed bars while auth overlay is active

 *   • body.navbar-collapse-open => hide bottom fixed bars while mobile navbar menu is expanded (fallback without :has)

 *   • body.guest-navbar-dropdown-open / .navbar-collapse-open => hide bottom fixed bars to avoid overlap

 *   • body.user-chat-panel-open / body.owner-chat-panel-open / body.chat-panel-open => hide bottom fixed bars while chat drawer is open

 *

 * Bootstrap dropdowns (in-place):

 *   • components/dropdown-saas.css sets .ce-dropdown-saas .dropdown-menu { z-index: var(--z-dropdown) }.

 *   • Navbar skins load later (navbar-unified.css / owner-navbar-unified.css) and set

 *     .navbar .dropdown-menu { z-index: var(--z-navbar-dropdown) } — same specificity (two classes),

 *     later cascade wins for menus inside .navbar. Use --z-navbar-dropdown for top-bar menus.

 *   • Teleported table/overflow menus: .dropdown-menu-teleported uses var(--z-dropdown-teleported)

 *     (below modal stack per ordering above). Do not ad-hoc calc(+N) above 1049 without updating

 *     design-tokens + this registry — breaks modal-backdrop (1050).

 *

 * Vendor overrides: third-party-z-index-overrides.css (spesso priorità massima vs z-index inline da JS).

 * Bootstrap modals: components/modal-stack-unified.css (body.modal-open) reinforces backdrop < .modal.show

 * on guest/user/owner (css-final-overrides) and admin master; nested modals may use inline z-index from BS.

 * ============================================

 */