/* ========================================
   Z-INDEX SCALE — single source of truth
   ========================================
   Always reference these variables instead of inventing new z-index values.
   Old offenders (10000, 99999) exist in builder.css, image-editor.css,
   dashboard.css — migrate them to variables as you touch each file.
   See CLAUDE.md "Z-index scale" for the documented table. */

:root {
    --z-base: 1;
    --z-elevated: 10;
    --z-dropdown: 50;
    --z-route-mask: 900;
    --z-sidebar-backdrop: 1040;
    --z-sidebar: 1050;
    --z-modal-backdrop: 1100;
    --z-modal: 1110;
    --z-side-panel: 1200;
    --z-toast: 1300;
    --z-tooltip: 1400;
    --z-image-editor: 1500;
    --z-critical: 1600;   /* session-expired overlay, critical alerts — always on top */
}