slide-making-skill

name	slide-making-skill
description	Implement single-slide PowerPoint pages with PptxGenJS. Use when writing or fixing slide JS files: dimensions, positioning, text/image/chart APIs, styling rules, and export expectations for native .pptx output.

PptxGenJS Slide Making Skill

This skill teaches how to generate native .pptx slides using PptxGenJS (JavaScript).

PptxGenJS Reference

Read pptxgenjs.md for the complete PptxGenJS API reference, including:

• Setup & basic structure
• Text & formatting
• Lists & bullets
• Shapes & shadows
• Images & icons
• Slide backgrounds
• Tables & charts

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Font Rules

Font Family Standards

Language	Default	Alternatives
Chinese	Microsoft YaHei (微软雅黑)	—
English	Arial	Georgia, Calibri, Cambria, Trebuchet MS

fontFace: "Microsoft YaHei"  // Chinese text
fontFace: "Arial"            // English text (or approved alternative)

Use system-safe fonts for cross-platform compatibility. Header/body can use different fonts (e.g., Georgia + Calibri).

No Bold for Body Text

Plain body text and caption/legend text must NOT use bold.

• Body paragraphs, descriptions → normal weight
• Captions, legends, footnotes → normal weight
• Reserve bold for titles and headings only

// ✅ Correct
slide.addText("Main Title", { bold: true, fontSize: 36, fontFace: "Arial" });
slide.addText("Body text here.", { bold: false, fontSize: 14, fontFace: "Arial" });

// ❌ Wrong
slide.addText("Body text here.", { bold: true, fontSize: 14 });

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Color Palette Rules (MANDATORY)

Strict Palette Adherence

Use ONLY the provided color palette. Do NOT create or modify colors.

• All colors must come from the user-provided palette
• Do NOT use colors outside the palette
• Do NOT modify palette colors (brightness, saturation, mixing)
• Only exception: Add transparency using the transparency property (0-100)

// ✅ Correct: Using palette colors
slide.addShape(pres.shapes.RECTANGLE, { fill: { color: theme.primary } });
slide.addText("Title", { color: theme.accent });

// ❌ Wrong: Colors outside palette
slide.addShape(pres.shapes.RECTANGLE, { fill: { color: "1a1a2e" } });

No Gradients

Gradients are prohibited. Use solid colors only.

// ✅ Correct: Solid colors
slide.background = { color: theme.bg };

// ✅ Correct: Solid + transparency for overlay
slide.addShape(pres.shapes.RECTANGLE, { fill: { color: theme.accent, transparency: 50 } });

No Animations

Animations and transitions are prohibited. All slides must be static.

---

Page Number Badge (REQUIRED)

All slides except Cover Page MUST include a page number badge in the bottom-right corner.

• Position: x: 9.3", y: 5.1"
• Show current number only (e.g. 3 or 03), NOT "3/12"
• Use palette colors, keep subtle

Circle Badge (Default)

slide.addShape(pres.shapes.OVAL, {
  x: 9.3, y: 5.1, w: 0.4, h: 0.4,
  fill: { color: theme.accent }
});
slide.addText("3", {
  x: 9.3, y: 5.1, w: 0.4, h: 0.4,
  fontSize: 12, fontFace: "Arial",
  color: "FFFFFF", bold: true,
  align: "center", valign: "middle"
});

Pill Badge

slide.addShape(pres.shapes.ROUNDED_RECTANGLE, {
  x: 9.1, y: 5.15, w: 0.6, h: 0.35,
  fill: { color: theme.accent },
  rectRadius: 0.15
});
slide.addText("03", {
  x: 9.1, y: 5.15, w: 0.6, h: 0.35,
  fontSize: 11, fontFace: "Arial",
  color: "FFFFFF", bold: true,
  align: "center", valign: "middle"
});

---

Theme Object Contract (MANDATORY)

The compile script passes a theme object with these exact keys:

Key	Purpose	Example
theme.primary	Darkest color, titles	"22223b"
theme.secondary	Dark accent, body text	"4a4e69"
theme.accent	Mid-tone accent	"9a8c98"
theme.light	Light accent	"c9ada7"
theme.bg	Background color	"f2e9e4"

NEVER use other key names like background, text, muted, darkest, lightest.

---

Subagent Output Format

Each subagent outputs a complete, runnable JS file:

// slide-01.js
const pptxgen = require("pptxgenjs");

const slideConfig = {
  type: 'cover',
  index: 1,
  title: 'Presentation Title'
};

// ⚠️ MUST be synchronous (not async)
function createSlide(pres, theme) {
  const slide = pres.addSlide();
  slide.background = { color: theme.bg };

  slide.addText(slideConfig.title, {
    x: 0.5, y: 2, w: 9, h: 1.2,
    fontSize: 48, fontFace: "Arial",  // English text uses Arial
    color: theme.primary, bold: true, align: "center"
  });

  return slide;
}

// Standalone preview - use slide-specific filename (slide-XX-preview.pptx)
if (require.main === module) {
  const pres = new pptxgen();
  pres.layout = 'LAYOUT_16x9';
  const theme = {
    primary: "22223b",
    secondary: "4a4e69",
    accent: "9a8c98",
    light: "c9ada7",
    bg: "f2e9e4"
  };
  createSlide(pres, theme);
  // Replace XX with actual slide index (01, 02, etc.) to avoid conflicts
  pres.writeFile({ fileName: "slide-01-preview.pptx" });
}

module.exports = { createSlide, slideConfig };

---

Critical Pitfalls

NEVER use async/await in createSlide()

// ❌ WRONG - compile.js won't await
async function createSlide(pres, theme) { ... }

// ✅ CORRECT
function createSlide(pres, theme) { ... }

NEVER use "#" with hex colors

color: "FF0000"      // ✅ CORRECT
color: "#FF0000"     // ❌ CORRUPTS FILE

NEVER encode opacity in hex strings

shadow: { color: "00000020" }              // ❌ CORRUPTS FILE
shadow: { color: "000000", opacity: 0.12 } // ✅ CORRECT

Prevent text wrapping in titles

// ✅ Use fit:'shrink' for long titles
slide.addText("Long Title Here", {
  x: 0.5, y: 2, w: 9, h: 1,
  fontSize: 48, fit: "shrink"
});

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Quick Reference

• Dimensions: 10" × 5.625" (LAYOUT_16x9)
• Colors: 6-char hex without # (e.g., "FF0000")
• English font: Arial (default), or approved alternatives
• Chinese font: Microsoft YaHei
• Page badge position: x: 9.3", y: 5.1"

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QA (Required)

Assume there are problems. Your job is to find them.

Your first render is almost never correct. Approach QA as a bug hunt, not a confirmation step. If you found zero issues on first inspection, you weren't looking hard enough.

Content QA

python -m markitdown slide-XX-preview.pptx

Check for missing content, typos, wrong order.

Check for leftover placeholder text:

python -m markitdown slide-XX-preview.pptx | grep -iE "xxxx|lorem|ipsum|placeholder"

If grep returns results, fix them before declaring success.

Verification Loop

1. Generate slide → Extract text with python -m markitdown slide-XX-preview.pptx → Review content
2. List issues found (if none found, look again more critically)
3. Fix issues
4. Re-verify — one fix often creates another problem
5. Repeat until verification reveals no new issues

Do not declare success until you've completed at least one fix-and-verify cycle.

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