/create-html-slides

name: frontend-slides
description: Create stunning, animation-rich HTML presentations from scratch or by converting PowerPoint files. Use when the user wants to build a presentation, convert a PPT/PPTX to web, or create slides for a talk/pitch. Helps non-designers discover their aesthetic through visual exploration rather than abstract choices.

> **Deprecated:** This skill is superseded by `goose-graphics`. See `skills/composites/goose-graphics/` (install with `npx goose-skills install goose-graphics`). The slides format is one of seven formats in the newer skill and supports 36 style presets plus image sourcing and PNG export. This skill is retained for one release cycle before removal.

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.

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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:

| 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 grid) | | Code slide | 1 heading + 8-10 lines of code maximum | | Quote slide | 1 quote (max 3 lines) + attribution | | Image slide | 1 heading + 1 image (max 60vh height) |

**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, 1.25