:root {
  --z-background: 10;
  --z-default: 11;
  --z-panel: 12;
  --z-tooltip: 13;
  --z-global-ui: 20; // i.e. menus, home buttons
  --z-modal: 30;
  --z-dialog: 31; // i.e. alerts
  --z-fx-sub: 39;
  --z-fx: 40;
  --z-fx-super: 41;
  --z-chrome: 42; // i.e. app-level, i.e. window title bar
  // Reserved for development stuff that must always be visible
  --z-dev: 50;
}