Frontend Slides

Frontend Slides Skill

Create zero-dependency, animation-rich HTML presentations that run entirely in the browser. This skill helps non-designers discover their preferred aesthetic through visual exploration ("show, don't tell"), then generates production-quality slide decks.

Core Philosophy

1. Zero Dependencies — Single HTML files with inline CSS/JS. No npm, no build tools.
2. Show, Don't Tell — People don't know what they want until they see it. Generate visual previews, not abstract choices.
3. Distinctive Design — Avoid generic "AI slop" aesthetics. Every presentation should feel custom-crafted.
4. Production Quality — Code should be well-commented, accessible, and performant.
5. Viewport Fitting (CRITICAL) — Every slide MUST fit exactly within the viewport. No scrolling within slides, ever. This is non-negotiable.

CRITICAL: Viewport Fitting Requirements

This section is mandatory for ALL presentations. Every slide must be fully visible without scrolling on any screen size.

The Golden Rule

Each slide = exactly one viewport height (100vh/100dvh)
Content overflows? → Split into multiple slides or reduce content
Never scroll within a slide.

Content Density Limits

To guarantee viewport fitting, enforce these limits per slide:

If content exceeds these limits → Split into multiple slides

Required CSS Architecture

Every presentation MUST include this base CSS for viewport fitting:

/* ===========================================
   VIEWPORT FITTING: MANDATORY BASE STYLES
   These styles MUST be included in every presentation.
   They ensure slides fit exactly in the viewport.
   =========================================== */

/* 1. Lock html/body to viewport */
html, body {
    height: 100%;
    overflow-x: hidden;
}

html {
    scroll-snap-type: y mandatory;
    scroll-behavior: smooth;
}

/* 2. Each slide = exact viewport height */
.slide {
    width: 100vw;
    height: 100vh;
    height: 100dvh; /* Dynamic viewport height for mobile browsers */
    overflow: hidden; /* CRITICAL: Prevent ANY overflow */
    scroll-snap-align: start;
    display: flex;
    flex-direction: column;
    position: relative;
}

/* 3. Content container with flex for centering */
.slide-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    max-height: 100%;
    overflow: hidden; /* Double-protection against overflow */
    padding: var(--slide-padding);
}

/* 4. ALL typography uses clamp() for responsive scaling */
:root {
    /* Titles scale from mobile to desktop */
    --title-size: clamp(1.5rem, 5vw, 4rem);
    --h2-size: clamp(1.25rem, 3.5vw, 2.5rem);
    --h3-size: clamp(1rem, 2.5vw, 1.75rem);

    /* Body text */
    --body-size: clamp(0.75rem, 1.5vw, 1.125rem);
    --small-size: clamp(0.65rem, 1vw, 0.875rem);

    /* Spacing scales with viewport */
    --slide-padding: clamp(1rem, 4vw, 4rem);
    --content-gap: clamp(0.5rem, 2vw, 2rem);
    --element-gap: clamp(0.25rem, 1vw, 1rem);
}

/* 5. Cards/containers use viewport-relative max sizes */
.card, .container, .content-box {
    max-width: min(90vw, 1000px);
    max-height: min(80vh, 700px);
}

/* 6. Lists auto-scale with viewport */
.feature-list, .bullet-list {
    gap: clamp(0.4rem, 1vh, 1rem);
}

.feature-list li, .bullet-list li {
    font-size: var(--body-size);
    line-height: 1.4;
}

/* 7. Grids adapt to available space */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(100%, 250px), 1fr));
    gap: clamp(0.5rem, 1.5vw, 1rem);
}

/* 8. Images constrained to viewport */
img, .image-container {
    max-width: 100%;
    max-height: min(50vh, 400px);
    object-fit: contain;
}

/* ===========================================
   RESPONSIVE BREAKPOINTS
   Aggressive scaling for smaller viewports
   =========================================== */

/* Short viewports (< 700px height) */
@media (max-height: 700px) {
    :root {
        --slide-padding: clamp(0.75rem, 3vw, 2rem);
        --content-gap: clamp(0.4rem, 1.5vw, 1rem);
        --title-size: clamp(1.25rem, 4.5vw, 2.5rem);
        --h2-size: clamp(1rem, 3vw, 1.75rem);
    }
}

/* Very short viewports (< 600px height) */
@media (max-height: 600px) {
    :root {
        --slide-padding: clamp(0.5rem, 2.5vw, 1.5rem);
        --content-gap: clamp(0.3rem, 1vw, 0.75rem);
        --title-size: clamp(1.1rem, 4vw, 2rem);
        --body-size: clamp(0.7rem, 1.2vw, 0.95rem);
    }

    /* Hide non-essential elements */
    .nav-dots, .keyboard-hint, .decorative {
        display: none;
    }
}

/* Extremely short (landscape phones, < 500px height) */
@media (max-height: 500px) {
    :root {
        --slide-padding: clamp(0.4rem, 2vw, 1rem);
        --title-size: clamp(1rem, 3.5vw, 1.5rem);
        --h2-size: clamp(0.9rem, 2.5vw, 1.25rem);
        --body-size: clamp(0.65rem, 1vw, 0.85rem);
    }
}

/* Narrow viewports (< 600px width) */
@media (max-width: 600px) {
    :root {
        --title-size: clamp(1.25rem, 7vw, 2.5rem);
    }

    /* Stack grids vertically */
    .grid {
        grid-template-columns: 1fr;
    }
}

/* ===========================================
   REDUCED MOTION
   Respect user preferences
   =========================================== */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        transition-duration: 0.2s !important;
    }

    html {
        scroll-behavior: auto;
    }
}

Overflow Prevention Checklist

Before generating any presentation, mentally verify:

1. ✅ Every .slide has height: 100vh; height: 100dvh; overflow: hidden;
2. ✅ All font sizes use clamp(min, preferred, max)
3. ✅ All spacing uses clamp() or viewport units
4. ✅ Content containers have max-height constraints
5. ✅ Images have max-height: min(50vh, 400px) or similar
6. ✅ Grids use auto-fit with minmax() for responsive columns
7. ✅ Breakpoints exist for heights: 700px, 600px, 500px
8. ✅ No fixed pixel heights on content elements
9. ✅ Content per slide respects density limits

When Content Doesn't Fit

If you find yourself with too much content:

DO:

• Split into multiple slides
• Reduce bullet points (max 5-6 per slide)
• Shorten text (aim for 1-2 lines per bullet)
• Use smaller code snippets
• Create a "continued" slide

DON'T:

• Reduce font size below readable limits
• Remove padding/spacing entirely
• Allow any scrolling
• Cram content to fit

Testing Viewport Fit

After generating, recommend the user test at these sizes:

• Desktop: 1920×1080, 1440×900, 1280×720
• Tablet: 1024×768, 768×1024 (portrait)
• Mobile: 375×667, 414×896
• Landscape phone: 667×375, 896×414

Phase 0: Detect Mode

First, determine what the user wants:

Mode A: New Presentation

• User wants to create slides from scratch
• Proceed to Phase 1 (Content Discovery)

Mode B: PPT Conversion

• User has a PowerPoint file (.ppt, .pptx) to convert
• Proceed to Phase 4 (PPT Extraction)

Mode C: Existing Presentation Enhancement

• User has an HTML presentation and wants to improve it
• Read the existing file, understand the structure, then enhance

Phase 1: Content Discovery (New Presentations)

Before designing, understand the content. Ask via AskUserQuestion:

Step 1.1: Presentation Context

Question 1: Purpose

• Header: "Purpose"
• Question: "What is this presentation for?"
• Options:
  • "Pitch deck" — Selling an idea, product, or company to investors/clients
  • "Teaching/Tutorial" — Explaining concepts, how-to guides, educational content
  • "Conference talk" — Speaking at an event, tech talk, keynote
  • "Internal presentation" — Team updates, strategy meetings, company updates

Question 2: Slide Count

• Header: "Length"
• Question: "Approximately how many slides?"
• Options:
  • "Short (5-10)" — Quick pitch, lightning talk
  • "Medium (10-20)" — Standard presentation
  • "Long (20+)" — Deep dive, comprehensive talk

Question 3: Content

• Header: "Content"
• Question: "Do you have the content ready, or do you need help structuring it?"
• Options:
  • "I have all content ready" — Just need to design the presentation
  • "I have rough notes" — Need help organizing into slides
  • "I have a topic only" — Need help creating the full outline

If user has content, ask them to share it (text, bullet points, images, etc.).

Phase 2: Style Discovery (Visual Exploration)

CRITICAL: This is the "show, don't tell" phase.

Most people can't articulate design preferences in words. Instead of asking "do you want minimalist or bold?", we generate mini-previews and let them react.

How Users Choose Presets

Users can select a style in two ways:

Option A: Guided Discovery (Default)

• User answers mood questions
• Skill generates 3 preview files based on their answers
• User views previews in browser and picks their favorite
• This is best for users who don't have a specific style in mind

Option B: Direct Selection

• If user already knows what they want, they can request a preset by name
• Example: "Use the Bold Signal style" or "I want something like Dark Botanical"
• Skip to Phase 3 immediately

Available Presets:

Step 2.0: Style Path Selection

First, ask how the user wants to choose their style:

Question: Style Selection Method

• Header: "Style"
• Question: "How would you like to choose your presentation style?"
• Options:
  • "Show me options" — Generate 3 previews based on my needs (recommended for most users)
  • "I know what I want" — Let me pick from the preset list directly

If "Show me options" → Continue to Step 2.1 (Mood Selection)

If "I know what I want" → Show preset picker:

Question: Pick a Preset

• Header: "Preset"
• Question: "Which style would you like to use?"
• Options:
  • "Bold Signal" — Vibrant card on dark, confident and high-impact
  • "Dark Botanical" — Elegant dark with soft abstract shapes
  • "Notebook Tabs" — Editorial paper look with colorful section tabs
  • "Pastel Geometry" — Friendly pastels with decorative pills

(If user picks one, skip to Phase 3. If they want to see more options, show additional presets or proceed to guided discovery.)

Step 2.1: Mood Selection (Guided Discovery)

Question 1: Feeling

• Header: "Vibe"
• Question: "What feeling should the audience have when viewing your slides?"
• Options:
  • "Impressed/Confident" — Professional, trustworthy, this team knows what they're doing
  • "Excited/Energized" — Innovative, bold, this is the future
  • "Calm/Focused" — Clear, thoughtful, easy to follow
  • "Inspired/Moved" — Emotional, storytelling, memorable
• multiSelect: true (can choose up to 2)

Step 2.2: Generate Style Previews

Based on their mood selection, generate 3 distinct style previews as mini HTML files in a temporary directory. Each preview should be a single title slide showing:

• Typography (font choices, heading/body hierarchy)
• Color palette (background, accent, text colors)
• Animation style (how elements enter)
• Overall aesthetic feel

Preview Styles to Consider (pick 3 based on mood):

IMPORTANT: Never use these generic patterns:

• Purple gradients on white backgrounds
• Inter, Roboto, or system fonts
• Standard blue primary colors
• Predictable hero layouts

Instead, use distinctive choices:

• Unique font pairings (Clash Display, Satoshi, Cormorant Garamond, DM Sans, etc.)
• Cohesive color themes with personality
• Atmospheric backgrounds (gradients, subtle patterns, depth)
• Signature animation moments

Step 2.3: Present Previews

Create the previews in: .claude-design/slide-previews/

.claude-design/slide-previews/
├── style-a.html   # First style option
├── style-b.html   # Second style option
├── style-c.html   # Third style option
└── assets/        # Any shared assets

Each preview file should be:

• Self-contained (inline CSS/JS)
• A single "title slide" showing the aesthetic
• Animated to demonstrate motion style
• ~50-100 lines, not a full presentation

Present to user:

I've created 3 style previews for you to compare:

**Style A: [Name]** — [1 sentence description]
**Style B: [Name]** — [1 sentence description]
**Style C: [Name]** — [1 sentence description]

Open each file to see them in action:
- .claude-design/slide-previews/style-a.html
- .claude-design/slide-previews/style-b.html
- .claude-design/slide-previews/style-c.html

Take a look and tell me:
1. Which style resonates most?
2. What do you like about it?
3. Anything you'd change?

Then use AskUserQuestion:

Question: Pick Your Style

• Header: "Style"
• Question: "Which style preview do you prefer?"
• Options:
  • "Style A: [Name]" — [Brief description]
  • "Style B: [Name]" — [Brief description]
  • "Style C: [Name]" — [Brief description]
  • "Mix elements" — Combine aspects from different styles

If "Mix elements", ask for specifics.

Phase 3: Generate Presentation

Now generate the full presentation based on:

• Content from Phase 1
• Style from Phase 2

File Structure

For single presentations:

presentation.html    # Self-contained presentation
assets/              # Images, if any

For projects with multiple presentations:

[presentation-name].html
[presentation-name]-assets/

HTML Architecture

Follow this structure for all presentations:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Presentation Title</title>

    <!-- Fonts (use Fontshare or Google Fonts) -->
    <link rel="stylesheet" href="https://api.fontshare.com/v2/css?f[]=...">

    <style>
        /* ===========================================
           CSS CUSTOM PROPERTIES (THEME)
           Easy to modify: change these to change the whole look
           =========================================== */
        :root {
            /* Colors */
            --bg-primary: #0a0f1c;
            --bg-secondary: #111827;
            --text-primary: #ffffff;
            --text-secondary: #9ca3af;
            --accent: #00ffcc;
            --accent-glow: rgba(0, 255, 204, 0.3);

            /* Typography - MUST use clamp() for responsive scaling */
            --font-display: 'Clash Display', sans-serif;
            --font-body: 'Satoshi', sans-serif;
            --title-size: clamp(2rem, 6vw, 5rem);
            --subtitle-size: clamp(0.875rem, 2vw, 1.25rem);
            --body-size: clamp(0.75rem, 1.2vw, 1rem);

            /* Spacing - MUST use clamp() for responsive scaling */
            --slide-padding: clamp(1.5rem, 4vw, 4rem);
            --content-gap: clamp(1rem, 2vw, 2rem);

            /* Animation */
            --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);
            --duration-normal: 0.6s;
        }

        /* ===========================================
           BASE STYLES
           =========================================== */
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        html {
            scroll-behavior: smooth;
            scroll-snap-type: y mandatory;
            height: 100%;
        }

        body {
            font-family: var(--font-body);
            background: var(--bg-primary);
            color: var(--text-primary);
            overflow-x: hidden;
            height: 100%;
        }

        /* ===========================================
           SLIDE CONTAINER
           CRITICAL: Each slide MUST fit exactly in viewport
           - Use height: 100vh (NOT min-height)
           - Use overflow: hidden to prevent scroll
           - Content must scale with clamp() values
           =========================================== */
        .slide {
            width: 100vw;
            height: 100vh; /* EXACT viewport height - no scrolling */
            height: 100dvh; /* Dynamic viewport height for mobile */
            padding: var(--slide-padding);
            scroll-snap-align: start;
            display: flex;
            flex-direction: column;
            justify-content: center;
            position: relative;
            overflow: hidden; /* Prevent any content overflow */
        }

        /* Content wrapper that prevents overflow */
        .slide-content {
            flex: 1;
            display: flex;
            flex-direction: column;
            justify-content: center;
            max-height: 100%;
            overflow: hidden;
        }

        /* ===========================================
           RESPONSIVE BREAKPOINTS
           Adjust content for different screen sizes
           =========================================== */
        @media (max-height: 600px) {
            :root {
                --slide-padding: clamp(1rem, 3vw, 2rem);
                --content-gap: clamp(0.5rem, 1.5vw, 1rem);
            }
        }

        @media (max-width: 768px) {
            :root {
                --title-size: clamp(1.5rem, 8vw, 3rem);
            }
        }

        @media (max-height: 500px) and (orientation: landscape) {
            /* Extra compact for landscape phones */
            :root {
                --title-size: clamp(1.25rem, 5vw, 2rem);
                --slide-padding: clamp(0.75rem, 2vw, 1.5rem);
            }
        }

        /* ===========================================
           ANIMATIONS
           Trigger via .visible class (added by JS on scroll)
           =========================================== */
        .reveal {
            opacity: 0;
            transform: translateY(30px);
            transition: opacity var(--duration-normal) var(--ease-out-expo),
                        transform var(--duration-normal) var(--ease-out-expo);
        }

        .slide.visible .reveal {
            opacity: 1;
            transform: translateY(0);
        }

        /* Stagger children */
        .reveal:nth-child(1) { transition-delay: 0.1s; }
        .reveal:nth-child(2) { transition-delay: 0.2s; }
        .reveal:nth-child(3) { transition-delay: 0.3s; }
        .reveal:nth-child(4) { transition-delay: 0.4s; }

        /* ... more styles ... */
    </style>
</head>
<body>
    <!-- Progress bar (optional) -->
    <div class="progress-bar"></div>

    <!-- Navigation dots (optional) -->
    <nav class="nav-dots">
        <!-- Generated by JS -->
    </nav>

    <!-- Slides -->
    <section class="slide title-slide">
        <h1 class="reveal">Presentation Title</h1>
        <p class="reveal">Subtitle or author</p>
    </section>

    <section class="slide">
        <h2 class="reveal">Slide Title</h2>
        <p class="reveal">Content...</p>
    </section>

    <!-- More slides... -->

    <script>
        /* ===========================================
           SLIDE PRESENTATION CONTROLLER
           Handles navigation, animations, and interactions
           =========================================== */

        class SlidePresentation {
            constructor() {
                // ... initialization
            }

            // ... methods
        }

        // Initialize
        new SlidePresentation();
    </script>
</body>
</html>

Required JavaScript Features

Every presentation should include:

1. SlidePresentation Class — Main controller

   • Keyboard navigation (arrows, space)
   • Touch/swipe support
   • Mouse wheel navigation
   • Progress bar updates
   • Navigation dots

2. Intersection Observer — For scroll-triggered animations

   • Add .visible class when slides enter viewport
   • Trigger CSS animations efficiently

3. Optional Enhancements (based on style):

   • Custom cursor with trail
   • Particle system background (canvas)
   • Parallax effects
   • 3D tilt on hover
   • Magnetic buttons
   • Counter animations

Code Quality Requirements

Comments: Every section should have clear comments explaining:

• What it does
• Why it exists
• How to modify it

/* ===========================================
   CUSTOM CURSOR
   Creates a stylized cursor that follows mouse with a trail effect.
   - Uses lerp (linear interpolation) for smooth movement
   - Grows larger when hovering over interactive elements
   =========================================== */
class CustomCursor {
    constructor() {
        // ...
    }
}

Accessibility:

• Semantic HTML (<section>, <nav>, <main>)
• Keyboard navigation works
• ARIA labels where needed
• Reduced motion support

@media (prefers-reduced-motion: reduce) {
    .reveal {
        transition: opacity 0.3s ease;
        transform: none;
    }
}

Responsive & Viewport Fitting (CRITICAL):

See the "CRITICAL: Viewport Fitting Requirements" section above for complete CSS and guidelines.

Quick reference:

• Every .slide must have height: 100vh; height: 100dvh; overflow: hidden;
• All typography and spacing must use clamp()
• Respect content density limits (max 4-6 bullets, max 6 cards, etc.)
• Include breakpoints for heights: 700px, 600px, 500px
• When content doesn't fit → split into multiple slides, never scroll

Phase 4: PPT Conversion

When converting PowerPoint files:

Step 4.1: Extract Content

Use Python with python-pptx to extract:

from pptx import Presentation
from pptx.util import Inches, Pt
import json
import os
import base64

def extract_pptx(file_path, output_dir):
    """
    Extract all content from a PowerPoint file.
    Returns a JSON structure with slides, text, and images.
    """
    prs = Presentation(file_path)
    slides_data = []

    # Create assets directory
    assets_dir = os.path.join(output_dir, 'assets')
    os.makedirs(assets_dir, exist_ok=True)

    for slide_num, slide in enumerate(prs.slides):
        slide_data = {
            'number': slide_num + 1,
            'title': '',
            'content': [],
            'images': [],
            'notes': ''
        }

        for shape in slide.shapes:
            # Extract title
            if shape.has_text_frame:
                if shape == slide.shapes.title:
                    slide_data['title'] = shape.text
                else:
                    slide_data['content'].append({
                        'type': 'text',
                        'content': shape.text
                    })

            # Extract images
            if shape.shape_type == 13:  # Picture
                image = shape.image
                image_bytes = image.blob
                image_ext = image.ext
                image_name = f"slide{slide_num + 1}_img{len(slide_data['images']) + 1}.{image_ext}"
                image_path = os.path.join(assets_dir, image_name)

                with open(image_path, 'wb') as f:
                    f.write(image_bytes)

                slide_data['images'].append({
                    'path': f"assets/{image_name}",
                    'width': shape.width,
                    'height': shape.height
                })

        # Extract notes
        if slide.has_notes_slide:
            notes_frame = slide.notes_slide.notes_text_frame
            slide_data['notes'] = notes_frame.text

        slides_data.append(slide_data)

    return slides_data

Step 4.2: Confirm Content Structure

Present the extracted content to the user:

I've extracted the following from your PowerPoint:

**Slide 1: [Title]**
- [Content summary]
- Images: [count]

**Slide 2: [Title]**
- [Content summary]
- Images: [count]

...

All images have been saved to the assets folder.

Does this look correct? Should I proceed with style selection?

Step 4.3: Style Selection

Proceed to Phase 2 (Style Discovery) with the extracted content in mind.

Step 4.4: Generate HTML

Convert the extracted content into the chosen style, preserving:

• All text content
• All images (referenced from assets folder)
• Slide order
• Any speaker notes (as HTML comments or separate file)

Phase 5: Delivery

Final Output

When the presentation is complete:

1. Clean up temporary files

   • Delete .claude-design/slide-previews/ if it exists

2. Open the presentation

   • Use open [filename].html to launch in browser

3. Provide summary

Your presentation is ready!

📁 File: [filename].html
🎨 Style: [Style Name]
📊 Slides: [count]

**Navigation:**
- Arrow keys (← →) or Space to navigate
- Scroll/swipe also works
- Click the dots on the right to jump to a slide

**To customize:**
- Colors: Look for `:root` CSS variables at the top
- Fonts: Change the Fontshare/Google Fonts link
- Animations: Modify `.reveal` class timings

Would you like me to make any adjustments?

Style Reference: Effect → Feeling Mapping

Use this guide to match animations to intended feelings:

Dramatic / Cinematic

• Slow fade-ins (1-1.5s)
• Large scale transitions (0.9 → 1)
• Dark backgrounds with spotlight effects
• Parallax scrolling
• Full-bleed images

Techy / Futuristic

• Neon glow effects (box-shadow with accent color)
• Particle systems (canvas background)
• Grid patterns
• Monospace fonts for accents
• Glitch or scramble text effects
• Cyan, magenta, electric blue palette

Playful / Friendly

• Bouncy easing (spring physics)
• Rounded corners (large radius)
• Pastel or bright colors
• Floating/bobbing animations
• Hand-drawn or illustrated elements

Professional / Corporate

• Subtle, fast animations (200-300ms)
• Clean sans-serif fonts
• Navy, slate, or charcoal backgrounds
• Precise spacing and alignment
• Minimal decorative elements
• Data visualization focus

Calm / Minimal

• Very slow, subtle motion
• High whitespace
• Muted color palette
• Serif typography
• Generous padding
• Content-focused, no distractions

Editorial / Magazine

• Strong typography hierarchy
• Pull quotes and callouts
• Image-text interplay
• Grid-breaking layouts
• Serif headlines, sans-serif body
• Black and white with one accent

Animation Patterns Reference

Entrance Animations

/* Fade + Slide Up (most common) */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s var(--ease-out-expo),
                transform 0.6s var(--ease-out-expo);
}

.visible .reveal {
    opacity: 1;
    transform: translateY(0);
}

/* Scale In */
.reveal-scale {
    opacity: 0;
    transform: scale(0.9);
    transition: opacity 0.6s, transform 0.6s var(--ease-out-expo);
}

/* Slide from Left */
.reveal-left {
    opacity: 0;
    transform: translateX(-50px);
    transition: opacity 0.6s, transform 0.6s var(--ease-out-expo);
}

/* Blur In */
.reveal-blur {
    opacity: 0;
    filter: blur(10px);
    transition: opacity 0.8s, filter 0.8s var(--ease-out-expo);
}

Background Effects

/* Gradient Mesh */
.gradient-bg {
    background:
        radial-gradient(ellipse at 20% 80%, rgba(120, 0, 255, 0.3) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 20%, rgba(0, 255, 200, 0.2) 0%, transparent 50%),
        var(--bg-primary);
}

/* Noise Texture */
.noise-bg {
    background-image: url("data:image/svg+xml,..."); /* Inline SVG noise */
}

/* Grid Pattern */
.grid-bg {
    background-image:
        linear-gradient(rgba(255,255,255,0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,0.03) 1px, transparent 1px);
    background-size: 50px 50px;
}

Interactive Effects

/* 3D Tilt on Hover */
class TiltEffect {
    constructor(element) {
        this.element = element;
        this.element.style.transformStyle = 'preserve-3d';
        this.element.style.perspective = '1000px';
        this.bindEvents();
    }

    bindEvents() {
        this.element.addEventListener('mousemove', (e) => {
            const rect = this.element.getBoundingClientRect();
            const x = (e.clientX - rect.left) / rect.width - 0.5;
            const y = (e.clientY - rect.top) / rect.height - 0.5;

            this.element.style.transform = `
                rotateY(${x * 10}deg)
                rotateX(${-y * 10}deg)
            `;
        });

        this.element.addEventListener('mouseleave', () => {
            this.element.style.transform = 'rotateY(0) rotateX(0)';
        });
    }
}

Troubleshooting

Common Issues

Fonts not loading:

• Check Fontshare/Google Fonts URL
• Ensure font names match in CSS

Animations not triggering:

• Verify Intersection Observer is running
• Check that .visible class is being added

Scroll snap not working:

• Ensure scroll-snap-type on html/body
• Each slide needs scroll-snap-align: start

Mobile issues:

• Disable heavy effects at 768px breakpoint
• Test touch events
• Reduce particle count or disable canvas

Performance issues:

• Use will-change sparingly
• Prefer transform and opacity animations
• Throttle scroll/mousemove handlers

Related Skills

• learn — Generate FORZARA.md documentation for the presentation
• frontend-design — For more complex interactive pages beyond slides
• design-and-refine:design-lab — For iterating on component designs

Example Session Flow

1. User: "I want to create a pitch deck for my AI startup"
2. Skill asks about purpose, length, content
3. User shares their bullet points and key messages
4. Skill asks about desired feeling (Impressed + Excited)
5. Skill generates 3 style previews
6. User picks Style B (Neon Cyber), asks for darker background
7. Skill generates full presentation with all slides
8. Skill opens the presentation in browser
9. User requests tweaks to specific slides
10. Final presentation delivered

Conversion Session Flow

1. User: "Convert my slides.pptx to a web presentation"
2. Skill extracts content and images from PPT
3. Skill confirms extracted content with user
4. Skill asks about desired feeling/style
5. Skill generates style previews
6. User picks a style
7. Skill generates HTML presentation with preserved assets
8. Final presentation delivered

Phase 6: Editable PPTX Generation

When the user wants a native, editable PowerPoint file (not just HTML):

Prerequisites

pip install python-pptx  # Usually pre-installed
# LibreOffice is pre-installed on gLinux for preview

Workflow

1. HTML first — Create the HTML slides as visual "gold standard" (1280x720 fixed size)
2. Generate PPTX — Write a Python script using python-pptx to recreate the layout
3. Preview — libreoffice --headless --convert-to pdf --outdir /tmp/preview file.pptx
4. Iterate — Fix issues, re-generate, re-preview
5. Upload — gcloud storage cp file.pptx gs://... for reliable delivery

CRITICAL: Text Must Be Inside Shapes

NEVER create separate add_textbox() shapes overlaid on add_shape() rectangles. This causes misalignment in Google Slides and other renderers.

WRONG (causes misalignment):

# DON'T DO THIS
rect(slide, l, t, w, h, bg_color, border)  # Background rectangle
tx(slide, l+0.15, t+0.08, w-0.3, 0.3, title)  # Separate text overlay — WILL MISALIGN

CORRECT (text inside shape):

# DO THIS
sh = slide.shapes.add_shape(MSO_SHAPE.ROUNDED_RECTANGLE, Inches(l), Inches(t), Inches(w), Inches(h))
sh.fill.solid(); sh.fill.fore_color.rgb = bg_color
sh.line.color.rgb = border; sh.line.width = Pt(1.5)
tf = sh.text_frame; tf.word_wrap = True
tf.margin_left = Inches(0.15); tf.margin_right = Inches(0.15)
# Write text directly into the shape's text frame
p = tf.paragraphs[0]
run = p.add_run(); run.text = title
run.font.size = Pt(14); run.font.bold = True

PPTX Setup Boilerplate

from pptx import Presentation
from pptx.util import Inches, Pt
from pptx.dml.color import RGBColor
from pptx.enum.text import PP_ALIGN, MSO_ANCHOR
from pptx.enum.shapes import MSO_SHAPE

prs = Presentation()
prs.slide_width  = Inches(13.333)  # 16:9 widescreen
prs.slide_height = Inches(7.5)
BLANK = prs.slide_layouts[6]  # Blank layout

Common Patterns

Metric card (value + label inside colored shape):

def metric(slide, l, t, w, h, value, label, bg=RED, txt=WHITE):
    sh = slide.shapes.add_shape(MSO_SHAPE.ROUNDED_RECTANGLE, Inches(l), Inches(t), Inches(w), Inches(h))
    sh.fill.solid(); sh.fill.fore_color.rgb = bg
    sh.line.fill.background()
    try: sh.adjustments[0] = 0.12
    except: pass
    tf = sh.text_frame; tf.word_wrap = True
    tf.paragraphs[0].alignment = PP_ALIGN.CENTER
    p = tf.paragraphs[0]
    run = p.add_run(); run.text = value
    run.font.size = Pt(28); run.font.color.rgb = txt; run.font.bold = True
    p2 = tf.add_paragraph(); p2.alignment = PP_ALIGN.CENTER
    run2 = p2.add_run(); run2.text = label
    run2.font.size = Pt(11); run2.font.color.rgb = txt

Callout box (title + body inside rounded rectangle):

def callout(slide, l, t, w, h, title, body, bg, border):
    sh = slide.shapes.add_shape(MSO_SHAPE.ROUNDED_RECTANGLE, Inches(l), Inches(t), Inches(w), Inches(h))
    sh.fill.solid(); sh.fill.fore_color.rgb = bg
    sh.line.color.rgb = border; sh.line.width = Pt(1.5)
    tf = sh.text_frame; tf.word_wrap = True
    tf.margin_left = Inches(0.15); tf.margin_right = Inches(0.15)
    p = tf.paragraphs[0]
    run = p.add_run(); run.text = title
    run.font.size = Pt(14); run.font.bold = True
    p2 = tf.add_paragraph()
    run2 = p2.add_run(); run2.text = body
    run2.font.size = Pt(12); run2.font.color.rgb = RGBColor(0x5F, 0x63, 0x68)

Gotchas

• Yellow background + white text = invisible → Use black text on yellow
• Table header: Set c.fill.solid(); c.fill.fore_color.rgb = RED per cell, add white bold text
• Alternating rows: if i % 2 == 1: c.fill.solid(); c.fill.fore_color.rgb = BG_LGRAY
• Rounded corners: sh.adjustments[0] = 0.06 (callouts) to 0.12 (metric cards)
• LibreOffice --convert-to png only exports first slide; use PDF for all pages
• Google Workspace MCP supports Docs only, NOT Slides API — can't create Google Slides programmatically

Reference Template

Full working example: ~/gcs-mount/cc-pages/assets/gen-pptx-v3.py (10-slide GPU→TPU deck)