Single-page PPT authoring

Given:

• A target slide directory (typically .pptwork/<deck>/<slide-name>/)
• One outline entry (pageType, assetId, key content, source, transition)
• The deck exportMode (raster or editable)

Produce:

• design.md — frontmatter title + layout, then ## Content / ## Note / ## Design (all three sections must be non-empty)
• slide.html — single-file self-contained, with the ## Note text mirrored into a <script type="application/json" id="ppt-speaker-notes-json"> island

Out of scope: cross-page planning (use the ppt skill's story-planning phase), screenshots and visual QC (use the ppt skill's screenshot.mjs + visual-qc reference), exporting (use export.mjs), web search (use the host app's webfetch / websearch).

File contract

design.md

• frontmatter:
  • title (required)
  • layout (required, short English identifier matching the layout you used)
• body, three sections, all non-empty:
  • ## Content — page copy in human language: a conclusion-form complete-sentence title plus supporting bullets / short paragraphs.
  • ## Note — speaker notes in natural prose (not bullets).
  • ## Design — visual / engineering notes: layout choice rationale, transition from previous page, data source, TBD markers.
• No empty placeholders. "This is an introduction page" is not acceptable.
• Detailed schema → references/design-md-spec.md

slide.html

• Must be single-file self-contained: CSS in <style>, JS in <script>.
• Images: inline base64 or https CDN. Local relative paths (<img src="assets/...">, <link href="...">) are forbidden — they break in <iframe srcdoc> previews and in the static-server-based renderer unless the sidecar files happen to land next to the HTML.
• Fonts, chart.js, d3 etc.: load from https CDN.
• Mirror ## Note content into a <script type="application/json" id="ppt-speaker-notes-json">…</script> node. This is the only way speaker notes land in the exported PPTX.
• For the slide to render at the correct PowerPoint canvas size, set html, body { width: 1280px; height: 720px; overflow: hidden; }.
• Hard rules and common pitfalls → references/slide-html-rules.md (must read).
• If exportMode=editable, also follow references/editable-html-rules.md.

Workflow

1. Read context

Outline entry (pageType / assetId / key content / source / transition) + the existing slide skeleton (design.md is an empty template, slide.html may only have <html> head/tail) + exportMode.

2. Look up the layout (assets contract)

If the outline names an assetId, look it up under the sister ppt skill's ../ppt/assets/<bucket>/index.json and read the matching descriptor:

Default buckets live in the sister ppt skill at ../ppt/assets/corporate-light/ and ../ppt/assets/claude-warm/ (5 layouts each). Read index.json + the matching html/<id>.html when the outline names an assetId. If no bucket is configured, skip this step and write slide.html from scratch using references/slide-html-rules.md and references/ppt-best-practices.md as your composition guide.

Do not pick the assetId yourself — that's a story-planning decision, the outline already names it (or explicitly says "no preset, design from scratch").

3. Don't copy the template HTML wholesale

Borrow only the composition (version safe area, columns, hierarchy, slot positions). Replace all placeholder copy ("Acme Corp", "2024 Q3 revenue", "scene illustration", etc.) with the page's real content. Placeholder bleed into a finished deck is one of the most common authoring failures.

4. Write design.md first

In the order Content → Note → Design:

• ## Content: conclusion-form complete-sentence title (not a noun phrase) + supporting bullets / short paragraphs.
• ## Note: speaker notes, natural prose, not bullets.
• ## Design: layout choice rationale, transition cue, data source, TBD markers.

5. Then write slide.html

Drive the HTML from the Content section. Whenever the data fits, prefer visuals over plain text:

• Trends / proportions / comparisons → Chart.js (see references/diagram-and-chart.md).
• Flow / architecture / system boundary → inline SVG.
• Decorative imagery → base64 inline; for large images (>2MB) compress or use a remote CDN.
• Icons → use a remote https SVG icon library (Heroicons, Lucide, Feather, Tabler, etc.) or paste a single inline SVG.

If exportMode=editable, write the HTML as PowerPoint-native objects: real text nodes for important copy, simple solid-fill shapes for cards, real tables, extractable Chart.js data, and separated background decoration. Do not place important text inside SVG/canvas/images/pseudo-elements.

6. Sync Note into the HTML

Mirror the ## Note text into the <script type="application/json" id="ppt-speaker-notes-json">…</script> island. This is the only path for speaker notes to land in the exported PPTX.

7. Need an external fact?

If a single page is missing one number / fact / citation / competitor data point:

• Use the host app's built-in webfetch / websearch tool. This skill ships no web tool of its own.
• Append findings to .pptwork/<deck>/materials/research.md (so they don't pollute the main context across slides).
• Cite the fact in ## Design as source: research.md §<timestamp>.
• Do not fabricate numbers.

8. Self-check

• Any <img src="assets/..."> / <link href="..."> relative paths? Convert to base64 or remote https.
• Note section synced into the HTML?
• data-id / data-role attributes stable enough to support later edit / patch style touch-ups?

References (read on demand)

Decision rules

• User says "tweak a sentence" → use edit / patch to mutate the matching data-id node, keep the outer structure intact.
• User says "rework the layout" → rewrite the whole slide.html, but keep design.md's narrative intact.
• Existing raster / complex HTML deck now needs editable output → rewrite each page with a language model according to editable-html-rules.md; do not rely on a pure rule-based converter.
• Content is fundamentally about ratio / trend / comparison → lead with a chart, don't list raw numbers.
• Content is fundamentally about flow / architecture / boundary → lead with inline SVG, don't pile up paragraphs.
• A background / brand image is required → base64 inline; for large images (>2MB) compress first or use a remote CDN.
• Data is missing → use the host's webfetch/websearch, do not invent numbers.

Common pitfalls

• Leaving template placeholder copy in the finished page ("Acme Corp Case" in an unrelated deck).
• Data page that's just "numbers + a paragraph" with no chart.
• image-slot left with a "scene illustration" placeholder — the thumbnail will look empty.
• <img src="assets/diagram.png"> relative path — the iframe preview breaks.
• Forgot to mirror Note into #ppt-speaker-notes-json — exported PPTX has empty speaker notes.
• Title written as a noun phrase ("AI Agent market") instead of a conclusion sentence.
• Faked a number instead of running a quick fetch / asking the user.