/* ============================================
   RenDS — Primitive Z-Index Tokens
   ============================================
   Layering system. Uses defined levels to
   prevent z-index wars.

   Convention: each layer has a clear purpose.
   ============================================ */

:root {
  --z-behind:    -1;
  --z-base:       0;
  --z-raised:     1;     /* slightly above siblings */
  --z-dropdown:  10;     /* dropdown menus */
  --z-sticky:    20;     /* sticky headers, navbars */
  --z-overlay:   30;     /* overlays, backdrops */
  --z-modal:     40;     /* modals, dialogs */
  --z-popover:   50;     /* popovers, floating elements */
  --z-toast:     60;     /* toast notifications */
  --z-tooltip:   70;     /* tooltips (always on top) */
  --z-max:     9999;     /* escape hatch (use sparingly) */
}