Creating Revealjs Presentations

Purpose

Guide the agent to write production-ready Quarto Reveal.js slides in a single pass:

• Correct YAML configuration
• SCSS theme customization (variables + rules)
• Layout patterns (columns, absolute positioning, backgrounds)
• Extension usage (Font Awesome, embedio, editable)
• Accessibility and maintainability

When to Use This Skill

Use when:

• Creating new .qmd presentation files
• Writing or modifying SCSS themes for Reveal.js
• Adding extensions (icons, embeds, interactive elements)
• Troubleshooting slide rendering issues
• Converting content into slide format

Do NOT use when:

• Working with Quarto documents that are NOT presentations
• The task involves only HTML/PDF/DOCX output formats

Inputs and Outputs

Inputs:

• User's content requirements (topic, structure, style preferences)
• Existing .qmd files or SCSS to modify
• Design constraints (colors, fonts, branding)

Outputs:

• .qmd files with proper YAML frontmatter
• SCSS files with /*-- scss:defaults --*/ and /*-- scss:rules --*/ sections
• Extension installation commands when needed

Behavior and Guidelines

YAML Configuration

1. Theme layering: Use theme: [default, styles/custom.scss] — later entries override earlier ones.
2. Scroll View: Enable with scroll-view: true for Reveal.js v5 (Quarto 1.6+).
3. Title slide backgrounds: Use title-slide-attributes: with data- prefixed keys.

SCSS Structure

1. Two required sections:
   • /*-- scss:defaults --*/ for variables (colors, fonts, sizes)
   • /*-- scss:rules --*/ for CSS rules
2. Override specificity: Prefix rules with .reveal .slide to beat built-in styles.
3. Background image paths: Use url("../../../../../assets/...") from compiled CSS location (5 levels up).

Layout Patterns

1. Columns: Use :::: {.columns} with ::: {.column width="X%"} children.
2. Fit text: Wrap with ::: r-fit-text for auto-sizing headlines.
3. Stack: Use .r-stack to overlay elements revealed sequentially.
4. Absolute positioning: Add {.absolute top="X" left="Y"} to images/divs.
5. Vertical center: Use .center class for vertical centering.

Advanced Features

1. Fragments: 20+ animation effects (fade-*, highlight-*, grow, etc.) with fragment-index ordering.
2. Auto-animate: Automatic transitions between slides using data-id matching.
3. Vertical slides: Create slide stacks with navigation modes (linear/vertical/grid).
4. Parallax backgrounds: Scrolling background images for depth effect.
5. Presentation sizing: Control dimensions, margins, and scaling.

Extensions

1. Font Awesome: quarto add quarto-ext/fontawesome → {{< fa icon >}}
2. embedio: quarto add coatless-quarto/embedio → {{< revealjs file="..." >}}
3. editable: quarto add EmilHvitfeldt/quarto-revealjs-editable → drag/resize in preview

Accessibility

1. Background images cannot have alt text — add visible text descriptions.
2. Use title="..." in Font Awesome shortcodes.
3. Ensure color contrast (avoid pure black/white).

Step-by-Step Procedure

1. Clarify requirements: Ask about topic, slide count, style preferences, required extensions.

2. Set up YAML frontmatter:

   • Define format: revealjs with theme, transitions, slide-number
   • Add execute: echo: false for code-heavy slides
   • Reference reference.md § Minimal YAML Template

3. Create SCSS theme (if customizing):

   • Define color palette in scss:defaults ($body-bg, $body-color, $link-color)
   • Add font family and size variables
   • Write rules in scss:rules with .reveal .slide prefix

4. Author slide content:

   • Use ## for slide breaks (or --- for untitled slides)
   • Apply layout patterns from reference
   • Add speaker notes with ::: {.notes}

5. Install extensions (if needed):

   • Provide quarto add commands
   • Show YAML activation (revealjs-plugins, filters)

6. Validate:

   • Check quarto preview runs without errors
   • Verify Scroll View (R key) and Print View (?view=print)

7. Summarize what was created and any assumptions made.

Use of Reference Files

Load specific modules from resources/ based on task:

Examples

Example 1 – New presentation with custom theme

• User goal: "Create slides for a tech talk with dark theme and code highlighting"
• Expected behavior:
  1. Generate YAML with theme: [default, styles/dark.scss]
  2. Create SCSS with dark $body-bg, light $body-color
  3. Enable code-line-numbers: true, code-overflow: wrap
  4. Provide slide structure with ## headers

Example 2 – Add icons and embeds

• User goal: "Add GitHub icon and embed another slide deck"
• Expected behavior:
  1. Provide quarto add quarto-ext/fontawesome command
  2. Show {{< fa brands github >}} syntax
  3. Provide quarto add coatless-quarto/embedio command
  4. Show {{< revealjs file="other.html" >}} syntax

Example 3 – Fix background image not showing

• User goal: "My SCSS background-image doesn't work"
• Expected behavior:
  1. Diagnose path issue (CSS compiles to deep directory)
  2. Suggest url("../../../../../assets/images/bg.jpg") path
  3. Explain the 5-level depth from _output/index_files/libs/revealjs/dist/theme/