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Product Promo Animation

Turn a product brief into a broadcast-quality, single-file HTML animated promo video. This skill distills a pattern proven across multiple product launches (multi-dimensional tables, AI knowledge bases, collaborative document tools).

What this skill produces

A single self-contained .html file with:

• A 15-30s animation telling the product story scene-by-scene, driven by one GSAP timeline
• A four-aspect-ratio switcher (16:9 landscape, 4:3, 1:1, 9:16 portrait) with automatic layout reflow
• Polished SVG-only icons (zero emoji) + brand colors harvested from the product's official site
• Full playback controls (play/pause, replay, scrub, scene nav, aspect switcher, keyboard shortcuts)
• SEO video metadata (JSON-LD VideoObject, Open Graph, canonical)

When to use

Trigger when the user wants a product promo animation/video as HTML, typically supplying:

• A brief / PRD / markdown spec describing the product and the capabilities to highlight
• The product name and official website (for brand harvesting)
• Constraints: duration, visual style, reference videos, forbidden elements

Hard rules (non-negotiable)

These come from recurring user feedback; violating any one is a defect.

1. Zero emoji. Every icon must be an inline SVG <symbol>/<use> (24×24 viewBox, stroke="currentColor", fill="none", stroke-width 2, round caps/joins). Emoji render inconsistently and look unprofessional.
2. No purple/magenta gradients (unless the brand itself uses them). Default forbidden hexes: #722ED1, #EB2F96, #F472B6, #A855F7, #8B5CF6, #D946EF, #C026D3. Use brand-harmonious accents instead (teal #00C4B4, warm orange #FF7D00, success green #00B42A, gold #FFB800, rose #F53F3F).
3. Brand fidelity. Primary colors and logo must be harvested from the product's official site — never invented. The logo must appear (at least in the opening + closing scenes).
4. Single file. All CSS and JS inlined; only the animation library (GSAP) and the logo image are external.
5. Selectors must match real class names. A CSS rule targeting a class that doesn't exist silently does nothing. The validator catches this — never skip validation.
6. Timing consistency. The DURATION constant, the UI time label, the JSON-LD duration, and the timeline's real length must all agree.

Workflow

Copy this checklist into your working notes and track progress:

- [ ] Phase 1: Digest the brief
- [ ] Phase 2: Harvest brand identity
- [ ] Phase 3: Design the storyboard
- [ ] Phase 4: Start from the skeleton
- [ ] Phase 5: Build the scenes
- [ ] Phase 6: Choreograph the timeline
- [ ] Phase 7: Validate and deliver

Phase 1: Digest the brief

Read the user's requirement doc in full and extract a working sheet:

• Product: name, tagline, official URL
• Capabilities to highlight: the explicit feature list (these become the middle scenes)
• Duration target: e.g. "15-30s" → plan ~26s
• Hard constraints: forbidden colors, icon style, reference videos, output path
• Tone: from the requested marketing angle (e.g. "product marketing expert")

If the brief doesn't specify an output location, ask, or default to the brief's directory.

Phase 2: Harvest brand identity

Visit the product's official site to extract ground truth — do not guess:

• Primary color and gradient stops (inspect CSS / theme)
• Logo URL (download it beside the output file, e.g. ./assets/<product>-logo.png)
• Accent colors used in the design system
• Visual language: card styling, corner radius, shadows, typography

Record these as a "brand token" sheet and reuse it throughout. See references/architecture.md §Color System for the token structure.

Phase 3: Design the storyboard

Map capabilities onto a scene sequence. The proven structure is 8 scenes / ~26s (scale to 6-8 for shorter durations):

#	Scene archetype	Duration	Purpose
S1	Brand opening	~2.6s	Logo entrance + particles + product name + tagline
S2	Core editor/capability	~3.4s	Show the primary feature concretely
S3	Build/create	~3.4s	The signature "wow" workflow (e.g. drag-to-build)
S4	Multi-view/flexibility	~3.4s	Tabbed switch between multiple modes
S5	Ecosystem/integrations	~3.4s	Hub-and-spoke connections
S6	AI intelligence	~3.2s	Query → result → smart suggestions
S7	Real-time collaboration	~3.0s	Multi-user cursors, comments, presence
S8	Brand close	~3.8s	Logo breathing + tagline + capability chips + CTA

Produce a timing table with fixed scene marks (e.g. 0, 2.6, 6.0, 9.4, 12.8, 16.2, 19.4, 22.4) and, per scene, an element + animation-beat list. Pick only the archetypes that match the brief's capabilities; rename and reposition freely. See references/scene-recipes.md for each archetype's visual recipe and animation beats.

Phase 4: Start from the skeleton

Copy assets/skeleton.html to the output path. It contains the full infrastructure with {{PLACEHOLDER}} tokens:

• <head>: meta, JSON-LD VideoObject, OG tags, GSAP script tag
• CSS: stage + four-aspect variable system + scene/layout/control styles
• SVG symbol icon-library scaffold
• Two example scenes (S1 brand, S2 capability) demonstrating the DOM pattern
• Control bar HTML
• JS: fitStage, setAspect, timeline init, showScene/hideScene, updateProgress, scene nav, keyboard, controls auto-hide

Replace every {{TOKEN}}; no placeholder may remain. Understand the infrastructure before editing — see references/architecture.md.

Phase 5: Build the scenes

For each scene in the storyboard:

1. Define the SVG <symbol>s it needs in the icon library (reuse across scenes).
2. Write the scene DOM: .scene#sN > .grid-bg + .glow-orb* + .layout > (.left-copy + <graphic>).
3. .left-copy carries badge + title + subtitle + chip-row (the copy); the graphic container carries the visual demo.
4. Build all graphics from styled HTML/SVG divs — no external images except the logo.

Follow the DOM contract exactly so the responsive system works. See references/architecture.md §Scene DOM Contract.

Phase 6: Choreograph the timeline

Build the single gsap.timeline({ paused: true }). For each scene at mark TN:

• showScene('sN', TN), then a staggered .from() entrance: badge → title → subtitle → chips → graphic
• Graphic-specific beats (typing, dragging, count-up, path draw, tab switch, cursor move)
• hideScene('sN', TN + sceneDuration - 0.5) for the cross-fade

Set DURATION to the last scene's end. Wire updateProgress with the scene-marks array. See references/architecture.md §Animation Engine for reusable beat snippets (count-up, stroke-draw, typewriter, drag cursor, view switch).

Phase 7: Validate and deliver

Never deliver without running the validator.

python3 scripts/validate.py <output.html>

It checks: structure balance, zero emoji, forbidden colors, dead CSS selectors (rules targeting classes absent from the HTML), timing consistency, GSAP presence, JSON-LD presence. Fix everything it reports and re-run until it prints OK. (Diagnostics are bilingual — pass --lang zh for Chinese, or let it auto-detect your locale.)

Then do the browser pass per references/quality-checklist.md: console clean, all scenes activate in order, aspect switches reflow correctly (especially 9:16 — copy and graphic must stay grouped, never split), no overflow scrollbars.

Reference files

• references/architecture.md — full HTML/CSS/JS technical spec, color system, DOM contract, animation-engine snippets
• references/scene-recipes.md — visual recipes and animation beats for the 8 scene archetypes
• references/quality-checklist.md — static + browser validation gates and common defects
• assets/skeleton.html — copy-to-start template with the full infrastructure
• scripts/validate.py — deterministic static validator
• README.md — installation & usage across Codex / Claude Code / Cursor / Qoder

Anti-patterns learned in production

• Dead selector: writing .copy when the HTML class is .left-copy → the rule is silently ignored. Always cross-check class names; the validator enforces it.
• 9:16 layout split: using grid-template-rows: auto 1fr in stacked mode makes the graphic float in an over-tall row, separating it from the copy. Use auto auto + align-content: center.
• Timing drift: a yoyo/repeat tween pushes the timeline past DURATION. Compute the real end and sync all four duration references.
• Emoji leak: a stray ✓ or → in copy. Scan and replace with SVG.
• GSAP selector typo: writing #id .child when the element uses class="child" → empty-tween warning. Verify targets exist.