md-slides — Markdown deck → single-file HTML presentation

md-slides — Markdown deck → single-file HTML presentation

The slide-deck converter. Reads a markdown deck (HR or H1 boundaries, optional presenter notes), emits a single-file HTML presentation that runs in any browser with keyboard navigation, presenter mode, and print-to-PDF.

Three stdlib tools pipeline together:

slide_splitter.py  →  presenter_notes_parser.py  →  deck_html_renderer.py
   (md → ordered      (extract <!-- notes:         (slides + design-system
    slides with       --> blocks, attach            tokens → single-file
    titles)           per slide)                    HTML with keyboard nav)

When to invoke

Symptom	Action
markdown-html-orchestrator routes input as SLIDES	Invoke this skill
User runs /cs:md-slides <path>.md directly	Invoke this skill
Input has 3+ --- HR lines OR 5+ H1 headings with short bodies	Invoke this skill
Input is a long-form spec	Route to md-document instead
Input is a code review	Route to md-review instead
Input has no clear slide boundaries	Refuse, route to md-document
Input would produce 1 slide	Refuse (it's a poster)

Pipeline

# 1. Split slides on --- or H1 (auto-detect by default)
python3 markdown-html/skills/md-slides/scripts/slide_splitter.py \
    --input <path>.md --output /tmp/slides.json

# 2. Extract <!-- notes: ... --> blocks from each slide
python3 markdown-html/skills/md-slides/scripts/presenter_notes_parser.py \
    --slides /tmp/slides.json --output /tmp/deck.json

# 3. Render single-file HTML deck
python3 markdown-html/skills/md-slides/scripts/deck_html_renderer.py \
    --slides /tmp/deck.json --title "My Talk" --output deck.html

What ships in the HTML

• All slides as <section class="slide"> — one visible at a time, controlled by JS
• Keyboard nav — → / Space / PgDn advance; ← / PgUp previous; Home/End jump; P presenter mode; Esc exits presenter
• URL-hash deep linking — #3 jumps to slide 3; browser back/forward walks slides; share deck.html#5 to send someone directly there
• Progress bar — 3px at top showing position through the deck
• Slide counter — bottom-right ("3 / 12")
• Presenter mode (P key) — splits the window: current slide on left (60% width), panel on right with clock + speaker notes + next-slide preview
• Print stylesheet — Cmd+P produces a PDF with one slide per page
• @media (prefers-reduced-motion: reduce) honored
• 12 brand CSS custom properties from design-system; design_style affects layout density
• Reuses md-document's markdown parser — slide bodies render with consistent paragraph/list/code/table/callout handling

Hard rules

1. Refuses input with no clear slide boundaries. Auto mode needs ≥ 3 HR lines or ≥ 5 H1 headings. Otherwise exit 6 — route to md-document.
2. Refuses 1-slide decks. That's a poster, not a deck. Exit 5.
3. Refuses input < 100 lines. Same Shihipar threshold as all converters.
4. Refuses without onboarding. Same gate as every converter.
5. --strict-notes refuses < 50% notes coverage. A deck where most slides have no notes isn't set up for presenter mode. Exit 7.
6. Soft-warns slides > 40 source lines. Signal-to-noise; renders anyway but surfaces the count.
7. Single-file output. All CSS + JS inline. Only external is Google Fonts CSS. Prism.js is opt-in via --syntax.
8. No JS framework runtime. Vanilla JS + keyboard event handlers, no React/Vue/Svelte.

Forcing-question library (Matt Pocock grill discipline)

1. Is this actually a deck, or a long document? Recommended: if you can't draw clear slide boundaries, it's not a deck. Canon: Tufte Cognitive Style of PowerPoint.
2. HR (---) or H1 boundaries? Recommended: HR for typical decks; H1 for outline-driven decks. Canon: Marp / reveal.js / pandoc convergence.
3. Will it be presented live or distributed for self-paced reading? Recommended: live → need presenter notes; self-paced → notes optional. Canon: Weinschenk 100 Things Every Presenter Needs to Know.
4. Is there any slide over 40 source lines? Recommended: split it. Canon: NN/g — audience attention drops past ~6 bullets / 200 words.
5. Is --syntax needed? Recommended: only for decks with substantial code blocks. Default off. Canon: single-file shareability discipline.

Distinct from

• md-document — that's one continuous document. This is N discrete slides.
• md-review — that renders diff hunks + annotations. This renders prose slides.
• marketing/landing/ — that's a landing page, not a deck.
• Keynote / PowerPoint — those are graphic-design tools. This is for markdown-authored decks projected from a browser.

Output artifact

{default_output_dir}/deck-{slug}.html (path resolved by orchestrator's output_path_resolver.py; collision suffix -2, -3, … by default).

References

• Shihipar — Claude Code HTML output (Medium, 2026), Tier 3 use case "Slide Decks"
• Reynolds — Presentation Zen (less is more discipline)
• Atkinson — Beyond Bullet Points (the bullet-heavy failure mode)
• Tufte — The Cognitive Style of PowerPoint (the polemic)
• reveal.js / Big / Marp — convergent markdown-to-deck conventions
• See references/ for full citations (presentation_ux, keyboard_nav_patterns, single_file_deck_conventions)