The cascade is no longer a separate system — it's the existing state-presets + the
Material stagger + one foundation rule. Retires the --cascade-* reinvention.
- render-css: foundation structural-index writer — `[data-stagger] > *:nth-child` →
`--motion-stagger-index` (forward) / `:nth-last-child` → `--motion-stagger-index-rev`
(reverse). Nobody writes the index; soma never writes a visual var. Every preset's
enter/exit rule consumes it (parallel = `--motion-stagger-each` 0, cascade = N).
- Cascade rewritten as a thin EXPLICIT orchestrator: marks `[data-stagger]`, reflects
open→data-state, passes the preset to items via context; the `out:` retention flips
to data-state=closed (reusing the exit preset), reading the duration via dom.getWindow.
Drops the whole `--cascade-*` namespace + bespoke keyframes.
Docs: MOTION_SERVICE_RFC §D.11 — the final model (three orthogonal axes sema/motion/
eidos, the full lifecycle, the realization ladder snap->transition->animation->JS, the
firma-vs-realization seam, the cascade = existing system + one rule, the motion service
as the engine). eidos-motion aligned.
Verified: browser (enter scale-in/fade-in + nth-child index, exit reverse, zero inline
writes), npm run check 0 mine, motion.test 22/22, eidos-lint 0 invalid.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>