Frontend Slides

Create zero-dependency, animation-rich HTML presentations that run entirely in the browser.

Inspired by the visual exploration approach showcased in work by zarazhangrui (credit: @zarazhangrui).

When to Activate

Creating a talk deck, pitch deck, workshop deck, or internal presentation
Converting .ppt or .pptx slides into an HTML presentation
Improving an existing HTML presentation's layout, motion, or typography
Exploring presentation styles with a user who does not know their design preference yet

Non-Negotiables

Zero dependencies: default to one self-contained HTML file with inline CSS and JS.
Viewport fit is mandatory: every slide must fit inside one viewport with no internal scrolling.
Show, don't tell: use visual previews instead of abstract style questionnaires.
Distinctive design: avoid generic purple-gradient, Inter-on-white, template-looking decks.
Production quality: keep code commented, accessible, responsive, and performant.

Before generating, read STYLE_PRESETS.md for the viewport-safe CSS base, density limits, preset catalog, and CSS gotchas.

Workflow

1. Detect Mode

Choose one path:

New presentation: user has a topic, notes, or full draft
PPT conversion: user has .ppt or .pptx
Enhancement: user already has HTML slides and wants improvements

2. Discover Content

Ask only the minimum needed:

purpose: pitch, teaching, conference talk, internal update
length: short (5-10), medium (10-20), long (20+)
content state: finished copy, rough notes, topic only

If the user has content, ask them to paste it before styling.

3. Discover Style

Default to visual exploration.

If the user already knows the desired preset, skip previews and use it directly.

Otherwise:

Ask what feeling the deck should create: impressed, energized, focused, inspired.
Generate 3 single-slide preview files in .ecc-design/slide-previews/.
Each preview must be self-contained, show typography/color/motion clearly, and stay under roughly 100 lines of slide content.
Ask the user which preview to keep or what elements to mix.

Use the preset guide in STYLE_PRESETS.md when mapping mood to style.

4. Build the Presentation

Output either:

presentation.html
[presentation-name].html

Use an assets/ folder only when the deck contains extracted or user-supplied images.

Required structure:

semantic slide sections
a viewport-safe CSS base from STYLE_PRESETS.md
CSS custom properties for theme values
a presentation controller class for keyboard, wheel, and touch navigation
Intersection Observer for reveal animations
reduced-motion support

5. Enforce Viewport Fit

Treat this as a hard gate.

Rules:

every .slide must use height: 100vh; height: 100dvh; overflow: hidden;
all type and spacing must scale with clamp()
when content does not fit, split into multiple slides
never solve overflow by shrinking text below readable sizes
never allow scrollbars inside a slide

Use the density limits and mandatory CSS block in STYLE_PRESETS.md.

6. Validate

Check the finished deck at these sizes:

1920x1080
1280x720
768x1024
375x667
667x375

If browser automation is available, use it to verify no slide overflows and that keyboard navigation works.

7. Deliver

At handoff:

delete temporary preview files unless the user wants to keep them
open the deck with the platform-appropriate opener when useful
summarize file path, preset used, slide count, and easy theme customization points

Use the correct opener for the current OS:

macOS: open file.html
Linux: xdg-open file.html
Windows: start "" file.html

PPT / PPTX Conversion

For PowerPoint conversion:

Prefer python3 with python-pptx to extract text, images, and notes.
If python-pptx is unavailable, ask whether to install it or fall back to a manual/export-based workflow.
Preserve slide order, speaker notes, and extracted assets.
After extraction, run the same style-selection workflow as a new presentation.

Keep conversion cross-platform. Do not rely on macOS-only tools when Python can do the job.

Implementation Requirements

HTML / CSS

Use inline CSS and JS unless the user explicitly wants a multi-file project.
Fonts may come from Google Fonts or Fontshare.
Prefer atmospheric backgrounds, strong type hierarchy, and a clear visual direction.
Use abstract shapes, gradients, grids, noise, and geometry rather than illustrations.

JavaScript

Include:

keyboard navigation
touch / swipe navigation
mouse wheel navigation
progress indicator or slide index
reveal-on-enter animation triggers

Accessibility

use semantic structure (main, section, nav)
keep contrast readable
support keyboard-only navigation
respect prefers-reduced-motion

Content Density Limits

Use these maxima unless the user explicitly asks for denser slides and readability still holds:

| Slide type | Limit | |------------|-------| | Title | 1 heading + 1 subtitle + optional tagline | | Content | 1 heading + 4-6 bullets or 2 short paragraphs | | Feature grid | 6 cards max | | Code | 8-10 lines max | | Quote | 1 quote + attribution | | Image | 1 image constrained by viewport |

Anti-Patterns

generic startup gradients with no visual identity
system-font decks unless intentionally editorial
long bullet walls
code blocks that need scrolling
fixed-height content boxes that break on short screens
invalid negated CSS functions like -clamp(...)

Related ECC Skills

frontend-patterns for component and interaction patterns around the deck
liquid-glass-design when a presentation intentionally borrows Apple glass aesthetics
e2e-testing if you need automated browser verification for the final deck

Deliverable Checklist

presentation runs from a local file in a browser
every slide fits the viewport without scrolling
style is distinctive and intentional
animation is meaningful, not noisy
reduced motion is respected
file paths and customization points are explained at handoff