@pantoken/plugin-stacking

Named z-index depths from InstUI's view stacking scale — deepest, below, above, topmost — as --instui-stacking-* tokens plus .instui-stack-* utility classes.

import { toCss } from "@pantoken/css";
import { byTheme } from "@pantoken/tokens";
import { stacking } from "@pantoken/plugin-stacking";

const css = toCss(byTheme("rebrand"), { plugins: [stacking()] });

<div class="instui-view -position-relative instui-stack-above">…</div>

It defines both a tokens hook (bake --instui-stacking-* into any output) and a css hook (self-contained .instui-stack-* classes), so you pick the layer.