frontend-slides

name	frontend-slides
description	Create stunning, animation-rich HTML presentations locked to your brand identity. Use when the user wants to build a branded presentation, convert a PPT/PPTX to web, or create slides for a talk/pitch. On first use, a brand wizard walks you through defining your visual identity — every presentation after that is automatically on-brand.

Branded Frontend Slides

Create zero-dependency, animation-rich HTML presentations locked to your brand identity.

Core Principles

1. Zero Dependencies — Single HTML files with inline CSS/JS. No npm, no build tools.
2. Brand-Locked — Every presentation uses your brand's colors, fonts, logo, and visual signature. No style picker, no generic themes.
3. Distinctive Design — No generic "AI slop." Every presentation must feel custom-crafted for your brand.
4. Viewport Fitting (NON-NEGOTIABLE) — Every slide MUST fit exactly within 100vh. No scrolling within slides, ever. Content overflows? Split into multiple slides.

Design Aesthetics

You tend to converge toward generic, "on distribution" outputs. In frontend design, this creates what users call the "AI slop" aesthetic. Avoid this: make creative, distinctive frontends that surprise and delight — within the brand's visual identity.

Focus on:

• Typography: Use the brand's chosen fonts. Vary weights and sizes for hierarchy.
• Color & Theme: Commit to the brand palette. Use CSS variables for consistency. Dominant colors with sharp accents outperform timid, evenly-distributed palettes.
• Motion: Use animations for effects and micro-interactions. Focus on high-impact moments: one well-orchestrated page load with staggered reveals (animation-delay) creates more delight than scattered micro-interactions.
• Backgrounds: Create atmosphere and depth using brand colors. Layer CSS gradients, use geometric patterns, or add contextual effects that match the brand's signature elements.

Avoid generic AI-generated aesthetics:

• Overused font families (Inter, Roboto, Arial, system fonts) — unless the brand specifically chose them
• Cliched color schemes (particularly purple gradients on white)
• Predictable layouts and component patterns
• Cookie-cutter design that lacks context-specific character

Viewport Fitting Rules

These invariants apply to EVERY slide in EVERY presentation:

• Every .slide must have height: 100vh; height: 100dvh; overflow: hidden;
• ALL font sizes and spacing must use clamp(min, preferred, max) — never fixed px/rem
• Content containers need max-height constraints
• Images: max-height: min(50vh, 400px)
• Breakpoints required for heights: 700px, 600px, 500px
• Include prefers-reduced-motion support
• Never negate CSS functions directly (-clamp(), -min(), -max() are silently ignored) — use calc(-1 * clamp(...)) instead

When generating, read viewport-base.css and include its full contents in every presentation.

Content Density Limits Per Slide

Slide Type	Maximum Content
Title slide	1 heading + 1 subtitle + optional tagline
Content slide	1 heading + 4-6 bullet points OR 1 heading + 2 paragraphs
Feature grid	1 heading + 6 cards maximum (2x3 or 3x2)
Code slide	1 heading + 8-10 lines of code
Quote slide	1 quote (max 3 lines) + attribution
Image slide	1 heading + 1 image (max 60vh height)

Content exceeds limits? Split into multiple slides. Never cram, never scroll.

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Phase 0: Detect Mode

First: check if BRAND_CONFIG.md exists and is filled in (not just the empty template with <!-- ... --> placeholders).

• No brand config → Go to Phase 2 (Brand Wizard) before anything else.
• Brand config exists → Read it and proceed.

Then determine what the user wants:

• Mode A: New Presentation — Create from scratch. Go to Phase 1.
• Mode B: PPT Conversion — Convert a .pptx file. Go to Phase 4.
• Mode C: Enhancement — Improve an existing HTML presentation. Read it, understand it, enhance. Follow Mode C modification rules below.

Mode C: Modification Rules

When enhancing existing presentations, viewport fitting is the biggest risk:

1. Before adding content: Count existing elements, check against density limits
2. Adding images: Must have max-height: min(50vh, 400px). If slide already has max content, split into two slides
3. Adding text: Max 4-6 bullets per slide. Exceeds limits? Split into continuation slides
4. After ANY modification, verify: .slide has overflow: hidden, new elements use clamp(), images have viewport-relative max-height, content fits at 1280x720
5. Proactively reorganize: If modifications will cause overflow, automatically split content and inform the user. Don't wait to be asked

When adding images to existing slides: Move image to new slide or reduce other content first. Never add images without checking if existing content already fills the viewport.

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Phase 1: Content Discovery (New Presentations)

Ask ALL questions in a single AskUserQuestion call so the user fills everything out at once:

Question 1 — Purpose (header: "Purpose"): What is this presentation for? Options: Pitch deck / Teaching-Tutorial / Conference talk / Internal presentation

Question 2 — Length (header: "Length"): Approximately how many slides? Options: Short 5-10 / Medium 10-20 / Long 20+

Question 3 — Content (header: "Content"): Do you have content ready? Options: All content ready / Rough notes / Topic only

Question 4 — Inline Editing (header: "Editing"): Do you need to edit text directly in the browser after generation? Options:

• "Yes (Recommended)" — Can edit text in-browser, auto-save to localStorage, export file
• "No" — Presentation only, keeps file smaller

Remember the user's editing choice — it determines whether edit-related code is included in Phase 3.

If user has content, ask them to share it.

Step 1.2: Image Evaluation (if images provided)

If user selected "No images" -> skip to Phase 3.

If user provides an image folder:

1. Scan — List all image files (.png, .jpg, .svg, .webp, etc.)
2. View each image — Use the Read tool (Claude is multimodal)
3. Evaluate — For each: what it shows, USABLE or NOT USABLE (with reason), what concept it represents, dominant colors
4. Co-design the outline — Curated images inform slide structure alongside text. This is NOT "plan slides then add images" — design around both from the start (e.g., 3 screenshots -> 3 feature slides, 1 logo -> title/closing slide)
5. Confirm via AskUserQuestion (header: "Outline"): "Does this slide outline and image selection look right?" Options: Looks good / Adjust images / Adjust outline

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Phase 2: Brand Wizard

This phase runs once — when BRAND_CONFIG.md does not exist or is empty/unfilled. It creates the brand configuration that locks every future presentation to the user's visual identity.

Step 2.0: Brand Input

Ask how they want to define their brand (header: "Brand Setup"). The recommended path is "From an existing presentation" — most companies already have a deck template that codifies their visual identity (colors, fonts, logo, layout patterns) far more completely than any website does. Make this the first option and label it (Recommended).

• "From an existing presentation (Recommended)" — Extract brand from a PPT/HTML file they already use
• "From a website" — Extract the design system from a URL using dembrandt
• "From brand guidelines" — User provides a PDF, image, or description of their brand
• "From scratch" — Walk through each choice step by step

Why presentation-first: A deck template includes pre-resolved decisions (logo placement, slide layouts, color hierarchy, font weights for hero vs body) that a website does not. Websites optimize for scrolling and conversion; decks optimize for the same medium we're generating. Use this as the default unless the user specifically asks for one of the other paths.

Step 2.1: Gather Brand Identity

If "From an existing presentation" (recommended path):

1. Ask for the file. For .pptx, run python scripts/extract-pptx.py to extract content, then read the theme XML directly to get the full color scheme, font scheme, and embedded images.
2. When extracting logos from a PPTX, list ALL unique embedded images and their pixel dimensions — pick the highest-resolution variant (the wordmark is usually wider, e.g., ~889x269px; the monogram is ~177x137px). Read each candidate image visually before choosing. Embed the chosen logo as a base64 data URI in the brand config.
3. Verify base64 integrity before saving. Decode the base64 and check the resulting bytes are a valid PNG/JPEG (PNG signature: 89504e470d0a1a0a). Headless Chromium fails silently on corrupted images during PDF export — even if interactive Chrome appears to render them. If <img>.naturalWidth === 0 after load, the encoding is corrupt; re-encode from the source file.
4. Single-color logos: if the user only has one color variant (e.g., a black PNG) but needs it on both light and dark slides, use CSS filter: brightness(0) invert(1) to render it white on dark backgrounds — no need for a separate white asset.
5. Present what you found and ask the user to confirm or adjust.

If "From a website":

This path uses dembrandt — a tool that extracts a website's full design system (colors, typography, logo, borders, components) into design tokens in seconds.

1. Ask the user for the URL.

2. Prefer the dembrandt MCP server if it's connected (tools named get_brand_identity, get_color_palette, get_typography, get_design_tokens, get_component_styles, get_surfaces, get_spacing). Call get_brand_identity first for the high-level summary, then get_color_palette and get_typography for the specifics.

   If the MCP server is not connected, tell the user once: "I can extract richer brand data if you connect the dembrandt MCP server. To enable it, run: claude mcp add --transport stdio dembrandt -- npx -y dembrandt-mcp — but I'll proceed with the CLI now."

3. CLI fallback: Run npx -y dembrandt <url> --json-only via Bash and parse the resulting JSON. If the site is JavaScript-heavy or behind Cloudflare, retry with --slow or --browser=firefox.

4. From the extracted tokens, populate:

   • Colors: primary background, primary text, accent (look for the most-used non-neutral hue), and any secondary accents
   • Typography: display + body fonts, with the import URL (Google Fonts or Fontshare)
   • Logo: if dembrandt returns a logo URL, fetch the image and embed as a base64 data URI in the brand config (URLs break offline)
   • Feeling: infer from the palette and typography (e.g., dark + sans-serif + neon = "innovative, bold")

5. Watch for web-vs-deck font mismatches. A company's website often uses a commercial display font (e.g. "Factor A" via Adobe Fonts) that isn't on Google Fonts. If the user also has a deck template, ask whether they want the website's font (which may need a paid license) or the deck's font (which is usually already a Google Font). Suggest the closest free Google Fonts equivalent if needed.

6. Present what was extracted and ask the user to confirm or adjust each piece via AskUserQuestion.

If "From brand guidelines":

1. Ask the user to share the file
2. Read it and extract: color palette, typography, logo, visual principles
3. Present what you extracted and ask the user to confirm or adjust

If "From scratch":

Ask these questions in a single AskUserQuestion call:

• Company name (header: "Company"): text input
• Logo (header: "Logo"): "I'll paste/upload a logo" / "I don't have one yet"
• Color mood (header: "Colors"): Dark & bold / Light & clean / Colorful & energetic / Minimal & muted / "I have specific hex codes"
• Feeling (header: "Feeling", multiSelect: true, max 2): Confident & trustworthy / Innovative & bold / Calm & focused / Playful & approachable

Step 2.2: Choose Typography

Based on the brand mood and feeling, propose 2-3 font pairings (display + body). Use fonts from Google Fonts or Fontshare — never system fonts. Show the font names, weights, and a brief description of why they fit.

Ask the user to pick one, or suggest their own.

Step 2.3: Design Signature Elements

Based on everything gathered, propose 3 signature visual elements that will make the brand's slides distinctive. These are CSS-only patterns — no illustrations, no stock images. Examples:

• Thick accent bar on left edge of content slides
• Gradient mesh backgrounds with radial overlays in brand colors
• Floating geometric shapes (circles, lines) with brand accent
• Corner decorations using brand pattern
• Halftone dot overlay
• Diagonal split layouts with brand colors

Present the 3 proposals and let the user pick, modify, or request alternatives.

Step 2.4: Generate Preview

Generate a single title slide as an HTML file (.claude-design/brand-preview.html) that demonstrates the full brand identity: logo, colors, fonts, signature elements, and animations. Open it for the user.

Ask (header: "Brand Preview"): "Does this look right for your brand?" Options: Looks great / Adjust colors / Adjust fonts / Adjust layout / Start over

Iterate until the user approves.

Step 2.5: Save Brand Config

Once approved, write the final brand configuration to BRAND_CONFIG.md with all values filled in:

• Company name, tagline, website
• Logo (inline SVG or base64 data URI — never a URL that could break)
• Full CSS color palette
• Typography with font import URL
• Theme mode and feeling
• Signature elements with descriptions
• Slide type layouts (title, section, content, metrics, closing)

Delete .claude-design/brand-preview.html after saving.

Tell the user: "Your brand is saved. Every presentation from now on will use this identity. To change it later, just ask me to update the brand config."

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Phase 3: Generate Presentation

Generate the full presentation using content from Phase 1 and brand identity from BRAND_CONFIG.md.

Before generating, read these files:

• BRAND_CONFIG.md — Brand identity (colors, fonts, logo, signature elements, slide layouts)
• html-template.md — HTML architecture and JS features
• viewport-base.css — Mandatory CSS (include in full)
• animation-patterns.md — Animation reference

Key requirements:

• Single self-contained HTML file, all CSS/JS inline
• Include the FULL contents of viewport-base.css in the <style> block
• Use the exact fonts, colors, and CSS variables from BRAND_CONFIG.md. Note: Fontshare fonts have broken PostScript metadata that causes PDF export issues (see Phase 6B Font Safety). Google Fonts are recommended when PDF export is likely.
• Include the brand's logo on title and closing slides (and optionally as a small watermark on other slides, per the brand config's logo placement)
• Apply the brand's signature elements consistently across slides
• Follow the slide type layouts defined in the brand config
• Add detailed comments explaining each section
• Every section needs a clear /* === SECTION NAME === */ comment block

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Phase 4: PPT Conversion

When converting PowerPoint files:

1. Extract content — Run python scripts/extract-pptx.py <input.pptx> <output_dir> (install python-pptx if needed: pip install python-pptx)
2. Confirm with user — Present extracted slide titles, content summaries, and image counts
3. Check brand config — If BRAND_CONFIG.md doesn't exist, run Phase 2 first
4. Generate HTML — Convert to brand style, preserving all text, images (from assets/), slide order, and speaker notes (as HTML comments)

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Phase 5: Delivery

1. Clean up — Delete .claude-design/ if it exists
2. Open — Use open [filename].html to launch in browser
3. Summarize — Tell the user:
   • File location, slide count
   • Navigation: Arrow keys, Space, scroll/swipe, click nav dots
   • How to customize: :root CSS variables for colors, font link for typography, .reveal class for animations
   • If inline editing was enabled: Hover top-left corner or press E to enter edit mode, click any text to edit, Ctrl+S to save

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Phase 6: Share & Export (Optional)

After delivery, ask the user: "Would you like to share this presentation? I can deploy it to a live URL (works on any device including phones) or export it as a PDF."

Options:

• Deploy to URL — Shareable link that works on any device
• Export to PDF — Universal file for email, Slack, print
• Both
• No thanks

If the user declines, stop here. If they choose one or both, proceed below.

6A: Deploy to a Live URL (Vercel)

This deploys the presentation to Vercel — a free hosting platform. The link works on any device (phones, tablets, laptops) and stays live until the user takes it down.

If the user has never deployed before, guide them step by step:

1. Check if Vercel CLI is installed — Run npx vercel --version. If not found, install Node.js first (brew install node on macOS, or download from https://nodejs.org).

2. Check if user is logged in — Run npx vercel whoami.

   • If NOT logged in, explain: "Vercel is a free hosting service. You need an account to deploy. Let me walk you through it:"
     • Step 1: Ask user to go to https://vercel.com/signup in their browser
     • Step 2: They can sign up with GitHub, Google, email — whatever is easiest
     • Step 3: Once signed up, run vercel login and follow the prompts (it opens a browser window to authorize)
     • Step 4: Confirm login with vercel whoami
   • Wait for the user to confirm they're logged in before proceeding.

3. Deploy — Run the deploy script:

   bash scripts/deploy.sh <path-to-presentation>
   

   The script accepts either a folder (with index.html) or a single HTML file.

4. Share the URL — Tell the user:

   • The live URL (from the script output)
   • That it works on any device — they can text it, Slack it, email it
   • To take it down later: visit https://vercel.com/dashboard and delete the project
   • The Vercel free tier is generous — they won't be charged

Deployment gotchas:

• Local images/videos must travel with the HTML. The deploy script auto-detects files referenced via src="..." in the HTML and bundles them. But if the presentation references files via CSS background-image or unusual paths, those may be missed. Before deploying, verify: open the deployed URL and check that all images load. If any are broken, the safest fix is to put the HTML and all its assets into a single folder and deploy the folder instead of a standalone HTML file.
• Prefer folder deployments when the presentation has many assets. If the presentation lives in a folder with images alongside it (e.g., my-deck/index.html + my-deck/logo.png), deploy the folder directly: bash scripts/deploy.sh ./my-deck/. This is more reliable than deploying a single HTML file because the entire folder contents are uploaded as-is.
• Redeploying updates the same URL. Running the deploy script again on the same presentation overwrites the previous deployment. The URL stays the same — no need to share a new link.

6B: Export to PDF

Two export methods are available. Use the vector PDF method first — it's faster, produces dramatically smaller files (~130KB vs ~20MB), preserves selectable text, and renders instantly in macOS Preview. Fall back to the screenshot method only if you encounter rendering issues with specific visual effects.

Note: Animations and interactivity are not preserved in either method — the PDF is a static snapshot. This is normal and expected; mention it to the user so they're not surprised.

Method 1: Vector PDF (recommended)

Uses Chromium's native PDF renderer with font patching. Produces small, fast, text-selectable PDFs.

npx -p playwright node scripts/export-pdf.js <path-to-html> [output.pdf]

What happens behind the scenes:

• Detects Fontshare fonts and patches their broken PostScript name tables (see Font Safety below)
• Rewrites the DOM to disable scroll-snap and force proper page breaks
• Strips transparent gradient overlays that cause sluggish rendering in Preview
• Generates a native vector PDF at standard widescreen dimensions (960×540 pts)
• Linearizes the PDF with qpdf for progressive page loading

Prerequisites:

• npx playwright install chromium — browser engine
• pip3 install fonttools — font patching (only needed if Fontshare fonts are detected)
• brew install qpdf — PDF linearization (optional but recommended)

Typical result: 17-slide deck = ~130KB, instant page flips in Preview, selectable text.

Method 2: Screenshot PDF (fallback)

Captures each slide as a PNG screenshot and combines them into a PDF. Use this if Method 1 has rendering issues with specific visual effects (e.g., canvas animations, complex SVGs).

bash scripts/export-pdf.sh <path-to-html> [output.pdf]

Tradeoffs vs Method 1:

• File size: ~1-2MB per slide (vs ~8KB per slide with Method 1)
• Text is NOT selectable (it's images)
• macOS Preview may be sluggish with large files
• Use --compact flag for smaller files: bash scripts/export-pdf.sh <path> --compact

Font Safety (IMPORTANT)

Fontshare ships font files with broken metadata. The PostScript name, family name, and full name fields in Fontshare's TTF files are literally set to the string "false". This is not a Chromium bug — it's in the font binary itself. When Chromium embeds these fonts in a PDF, macOS Preview cannot cache or identify them, causing:

• Text blurs on every page flip, then re-renders after ~0.5 seconds
• Pages flash white when navigating
• Overall sluggish feel, as if the PDF has network dependencies

The vector PDF script (Method 1) fixes this automatically by downloading the TTF files, patching the name tables with Python fonttools, and injecting the corrected fonts as base64 during generation.

If you're choosing fonts for a new presentation and PDF export is likely needed, prefer Google Fonts. All Google Fonts have correct PostScript metadata and embed cleanly in PDFs without patching.

⚠ Other PDF export gotchas:

• Slides must use class="slide". Both export scripts find slides by querying .slide elements.
• Standard page dimensions matter. The vector PDF script generates at 1280×720 CSS pixels → 960×540 PDF points. This is the exact standard widescreen format that macOS Preview, Keynote, and PowerPoint are optimized for. Larger dimensions (e.g., 1920×1080 → 1440×810 pts) cause Preview to re-render pages on every flip.
• Transparent gradient overlays are expensive. ::before pseudo-elements with hsla() radial gradients create PDF transparency groups. The vector PDF script strips these automatically. The solid --bg-primary background looks clean without them.
• Linearization helps. qpdf --linearize reorganizes the PDF for progressive page loading. Without it, Preview may show white flashes between pages.

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Supporting Files

File	Purpose	When to Read
BRAND_CONFIG.md	Brand identity: colors, fonts, logo, signature elements, layouts	Phase 0 (always) + Phase 3
viewport-base.css	Mandatory responsive CSS — copy into every presentation	Phase 3 (generation)
html-template.md	HTML structure, JS features, code quality standards	Phase 3 (generation)
animation-patterns.md	CSS/JS animation snippets and effect-to-feeling guide	Phase 3 (generation)
scripts/extract-pptx.py	Python script for PPT content extraction	Phase 4 (conversion)
scripts/deploy.sh	Deploy slides to Vercel for instant sharing	Phase 6 (sharing)
scripts/export-pdf.js	Vector PDF export with font patching (recommended)	Phase 6 (PDF export)
scripts/export-pdf.sh	Screenshot-based PDF export (fallback)	Phase 6 (PDF export)