These are the SDX z-index values throughout the library:
- $zindex-ribbon: 10;
- $zindex-form: 100;
- $zindex-form-select: 500;
- $zindex-footer: 20000;
- $zindex-navigation: 50000;
- $zindex-scroll-to-top: 55000;
- $zindex-menu: 60000;
- $zindex-empty-state: 700000;
- $zindex-modal: 900000;
- $zindex-topmost: 999999;