# NEXT11 V6.33 R14 — In-player Demo + Smart Focus

Base: V6.33 R13.

Scope is reference-demo presentation only. No Nex motion, IK, resolved animation, camera, travel or coaching-cue content changed.

## What changed

- `Visa demo` no longer leaves the workout or opens a browser tab.
- The original exercise reference video opens as a full in-player overlay.
- Video height is the authority: the original film fills the maximum available player height.
- Horizontal crop is driven by `assets/js/data/nex-demo-focus-tracks.json`.
- Focus tracks are precomputed/curated for all 18 Dynamic Warmup exercises; the phone only interpolates a tiny X curve and does no live pose/CV analysis.
- Focus interpolation uses smoothstep plus temporal damping for non-jittery panning.
- Tap video toggles play/pause.
- Closing the demo returns to the same exercise and restores the coaching drawer if it was open before entering the demo.
- Demo UI uses restrained `ORIGINAL DEMO` chrome and a small close control.

## QA

- 18/18 media + focus-track coverage audit: PASS.
- JS syntax + track JSON validation: PASS.
- Real Chromium mobile runtime at 390×844 used for tracking checks.
- High Knee Tuck start/mid verified with the intended athlete centered.
- High Knee Run, Lateral Lunges and Toe Walk were allowed to play in real time while crop-left was logged; runtime pan changed with source motion rather than remaining static.
- `R14_DEMO_OVERLAY_FINAL_QA.jpg` contains representative mobile frames.

## Important architecture

Do not replace this with realtime MediaPipe/CV on the phone. The R14 focus tracks are deliberately precomputed so the demo overlay remains cheap and smooth on iPhone.