HTML Deck

Build a slide presentation as a single HTML file with fixed-size slides that letterbox to any viewport. A deck is fixed-canvas media (default 1920×1080, 16:9) — a different medium from responsive UI and from static posters.

When to use

Cross-surface handoff. A deck often consumes upstream analysis (spreadsheet → deck, research → deck). Read the handoff envelope from surface-agent-contracts: trust verification_already_done (don't recompute the source's numbers), carry the asset list, and keep source restrictions intact.

• The user asks for a deck, presentation, slides, or a pitch as a web/HTML deliverable.

When NOT to use: static single-image visual art (poster, PNG/PDF one-off) → canvas-design. Responsive product UI → fe-design + stack executor. Multiple styled options of one screen → design-variations.

Deck fidelity floor

The deck surface's floor (per surface-agent-contracts):

• Outline before slides. Draft the slide outline (title + one-line intent per slide) before building any slide; when audience or tone is ambiguous, ask once. (fixture: ssac-deck-missing-notes.)
• Labels + speaker notes. Every slide carries a stable label and speaker notes, not just on-slide text.
• Visual rhythm + readable scale. Consistent spacing/hierarchy across slides; never sub-readable text (the type floors below). (fixture: ssac-tiny-slide-text.)
• Image/asset provenance. Real assets via the project path, no invented brand evidence (design-fidelity § Asset & imagery discipline).
• Export verification. Verify the deck exports/renders (design-artifact-verification); on a host without export capability, say what could not be verified rather than claiming a clean export.

Procedure

1. Discovery. Confirm: audience (engineers / executives / customers — determines tone and density), aspect ratio (16:9 default), slide count vs time budget (~1 slide/minute; most decks land at 8–15), tone, source material (PRD/doc — read it before sketching), speaker notes (off unless requested), and the brand / design system. No brand → design-intelligence direction first. A fully specified ask ("5-slide deck for the all-hands from this PRD") skips the question round.
2. Commit to a layout system before any slide. 4–6 layout types (cover, section header, content, quote/pull-out, comparison two-column, closing/ CTA); per layout: background, headline size/position, body area, footer treatment. 1–2 background colors across the deck (section headers may break to a third). Record the system as a comment block at the top of the file.
3. Start from the deck-shell starter (templates/deck-shell.html, skill-local): fixed-canvas scaling + letterboxing, keyboard/tap navigation, slide counter, localStorage slide-index persistence, print-to-PDF CSS. Each slide is a direct child <section> with a 1-indexed data-screen-label ("01 Title") so the user can reference slides by the counter they see.
4. Build slide-by-slide, reveal early. Show the file at 1–2 slides — don't perfect 15 in private. Per slide: one primary message; type floors on a 1080p canvas: body ≥24px (32px+ preferred), headlines 60–96px+; tokens from the active brand/design system (precedence per brand-source-of-truth, emission per design-tokens); honest placeholders for missing imagery (striped background + monospace size label — see fe-design § Craft details); cut filler slides ("Why choose us?", "About this deck") and data that doesn't support the slide's point.
5. Speaker notes only when requested — as a toggleable overlay or per-slide <aside hidden>, never printed.
6. Quality gate. Run lint_design_slop over the file; honor the outward-artifact hygiene floor (Q13 in design-antipatterns.md) — no workspace paths, skill/tool names, or generator traces in markup or comments; final pass → design-review. Verify scaling + navigation + persistence once in a browser before delivery.

Output format

1. One self-contained HTML file built on the deck-shell: fixed-canvas <section> slides with 1-indexed data-screen-labels, letterbox scaling, keyboard/tap navigation, slide counter, localStorage persistence, print-to-PDF CSS.
2. Layout-system comment block at the top of the file naming the 4–6 layout types and the background-color budget.
3. Type-floor compliance — body ≥24px, headlines 60–96px+ on the 1080p canvas; deviations only with a stated reason.
4. Clean slop scan + Q13 — lint_design_slop findings resolved or DESIGN.md-justified; no system internals in the artifact.

Do NOT

• Do NOT hand-roll the scaling/navigation — start from the deck-shell starter; re-derived viewport math drifts.
• Do NOT use responsive units/breakpoints inside slides — a deck is fixed-canvas; the shell scales the whole stage.
• Do NOT drop body text below 24px on a 1080p canvas — projector legibility is the floor, not a preference.
• Do NOT pad with filler slides or invented stats — every slide earns its place.
• Do NOT introduce per-slide ad-hoc colors/spacing — the layout system from step 2 is the budget.
• Do NOT embed system internals (paths, skill/tool names, generator traces) in the file — Q13.

Gotcha

• localStorage persistence keys on location.pathname — two decks served from the same path share a slide index; rename the file per deck or extend the key when hosting several decks under one path.
• Print-to-PDF uses the fixed canvas per page: browsers map it onto the paper size — set the print dialog to landscape + "fit to page" or the slides clip; test one print preview before shipping a PDF.
• Emoji in slide headlines is the CP5 tell exactly as in product UI — the deck medium doesn't exempt it.

See also

• templates/deck-shell.html (skill-local) — the canonical shell; copy, don't re-derive.
• canvas-design — static posters/one-frame art (not decks).
• design-intelligence — direction/palette/type grounding.
• design-tokens / brand-to-tokens — token precedence and emission.
• design-review — final review gate.
• docs/guidelines/design-antipatterns.md — catalog, CP5, Q13.