PPT Slide Generator (프레젠테이션 슬라이드 자동 생성기)

This skill creates professional HTML-based presentation slides (1920x1080, 16:9) through a complete pipeline: theme selection, topic confirmation, deep research, 2-stage content review, AI image generation, and HTML generation with PDF download.

Output format fork — decide FIRST:
- Default deliverable (HTML → PDF): follow the steps below.
- Editable Google Slides deck requested (구글 슬라이드, Google Slides,
collaborative deck, redesigning an existing Slides deck): read
google-slides-export.md in this skill folder and build with python-pptx
instead of HTML. Content/research/review steps (0-3.5) still apply;
Step 4 (HTML) and the download button do not.
- Redesigning an existing deck from a PDF: skip research/outline gates —
extract content + page renders with PyMuPDF (fitz), keep copy 1:1,
redesign the template only.
- Both at once (PDF redesign → Google Slides): PDF-redesign rules govern
content (skip gates, copy 1:1); Google Slides rules govern build/delivery.

Step 0: Theme Selection + Topic Confirmation

First, check available themes:

Read the list of .md files in the themes/ folder (relative to this SKILL.md)
Present the available themes to the user and ask them to select one
Read the selected theme file to load the design system

Then confirm:

Topic — What is the presentation about?
Purpose — Business presentation or educational/lecture material?
Slide count preference — Short (5-8) / Normal (10-15) / Deep (16-25)
Presenter info — Name, date, contact (for cover and ending slides)

Don't over-interview. Get the topic confirmed and move to research quickly.

Step 1: Deep Research

Once topic is confirmed, do thorough web research. Research quality directly determines whether the presentation is valuable or just looks nice.

What to search for (5-10 searches)

Key statistics and recent numbers
Latest trends and market changes
Comparable data points for before/after or vs. comparisons
Visualizable data (percentages, growth rates, rankings)
Real examples or quotable insights
Source-backed facts (not vague claims)

Organize your research

After researching, compile:

Topic summary (1 line)
Key data points (5-8)
Chart-ready data (numbers that can become visuals)
Memorable example or quote
Key takeaways (3-5)

Step 1.5: Narrative Strategy

Design the presentation arc before writing the outline.

Opening (slides 1-3) must:

Hook the audience — a bold claim, surprising statistic, or provocative question
Establish the problem/opportunity clearly
Preview the value — "by the end of this presentation, you will..."

Middle (core slides):

Build logical progression — each slide sets up the next
Alternate between data/evidence slides and insight/implication slides
Place the strongest data point at the climax, not the beginning

Closing (last 2-3 slides):

Summarize key takeaways (no new information)
Clear call-to-action or next steps
End with impact — not a whimper

Step 2: Outline Review (Gate 1)

Present the slide outline to the user for review:

Slide 1 [Cover]: Title — "..."
Slide 2 [Agenda]: 3 sections
Slide 3 [Section Divider]: Section 1 — "..."
Slide 4 [Body-Text]: Key message — "..."
Slide 5 [Body-Data]: Chart — "..."
...
Slide N [Ending]: Thank you + contact

Revision loop: Wait for explicit approval before proceeding.

If the user requests changes: apply revisions and re-present the updated outline
Repeat until the user approves
If the user wants to change the topic direction significantly, go back to Step 1

Only proceed to Gate 2 after explicit approval.

Step 3: Detailed Content Review (Gate 2)

Present full text/data for each slide:

Slide 4 [Body-Text]
  Title: "AI 마케팅 도입률 현황"
  Bullet 1: "2026년 기준 글로벌 기업 72%가 ..."
  Bullet 2: "한국 시장은 ..."
  Source: McKinsey 2026 Report

Present ALL slides with their complete content. Wait for explicit approval.

Revision loop:

If the user requests changes: apply revisions to specific slides and re-present only the changed slides
Repeat until the user approves
If structural changes are needed (add/remove/reorder slides), go back to Gate 1

Only proceed to image generation after explicit approval.

Step 3.5: Image Generation (Optional)

After content approval, before HTML generation:

Analyze each slide and identify where images would enhance the presentation
Present image prompt proposals to the user:

`` Slide 1 [Cover]: Background — "Professional abstract geometric pattern in navy and gold tones" Slide 6 [Quote]: Illustration — "Business team collaborating with AI dashboard" → Approve / Edit prompt / Skip all images ``

For approved prompts, generate images using Gemini API
Embed generated images as base64 data:image/png;base64,... in the HTML

Gemini API Call

Model: gemini-3.1-flash-image-preview

Authentication: Uses GOOGLEAIAPI_KEY from global environment.

API pattern:

from google import genai
from google.genai import types

client = genai.Client()

response = client.models.generate_content(
    model="gemini-3.1-flash-image-preview",
    contents="Create a professional presentation background: [prompt]",
    config=types.GenerateContentConfig(
        response_modalities=['TEXT', 'IMAGE'],
        image_config=types.ImageConfig(
            aspect_ratio="16:9",  # for slide backgrounds
            image_size="2K"
        )
    )
)

for part in response.parts:
    if part.inline_data is not None:
        image = part.as_image()
        image.save("slide-bg.png")

Aspect ratios:

Slide backgrounds: 16:9
Inline illustrations: 4:3 or 1:1

Error Handling

All image generation failures are non-blocking:

API timeout → skip image, log warning
Rate limit → wait 5s, retry once, then skip
Invalid response → skip, proceed without image
User can skip image generation entirely

If any image fails, note which slides were intended to have images so the user can retry later.

Step 4: HTML Generation

Read the selected theme file and generate a single HTML file containing all slides.

Critical Rules

Rule 1: Static HTML only for slides. Every <div class="slide"> must exist directly in the <body>. Never generate slides with JavaScript. JS-generated slides won't render in preview.

Rule 2: JavaScript is only for the download button and slide navigator. No JS for slide rendering.

Rule 3: Use Pretendard font via CDN.

<link rel="stylesheet" href="https://cdn.jsdelivr.net/gh/orioncactus/[email protected]/dist/web/variable/pretendardvariable-dynamic-subset.min.css" />

:root {
  --font-main: 'Pretendard Variable', 'Pretendard', 'Apple SD Gothic Neo',
               'Malgun Gothic', 'NanumGothic', sans-serif;
}

* {
  word-break: keep-all;
  overflow-wrap: break-word;
}

word-break: keep-all is mandatory for Korean. Without it, the browser breaks lines in the middle of words (character by character), which looks broken. keep-all forces line breaks only at spaces, keeping Korean phrases intact.

Rule 4: Deliver the HTML file directly. One HTML file, no separate viewer.

Rule 5: Photos and headshots — use <img> with object-fit (vector-first path).

The PRIMARY export path is now Playwright (vector PDF, see Rule 6). Playwright honors object-fit: cover perfectly. The html2canvas raster path is fallback-only.

Use <img> for photos that need to fit a fixed-ratio container:

<img class="headshot" src="data:image/jpeg;base64,..." alt="Speaker name" />

.speaker-photo { width:520px; height:680px; overflow:hidden; }
.headshot { width:100%; height:100%; object-fit:cover; object-position:center top; }

Why not background-image: Chrome's Ctrl+P "Background graphics" checkbox is OFF by default — <div> with background-image disappears from the printed PDF. <img> always renders. This was a real Dave Kim deck bug.

The old html2canvas-friendly background-image pattern is still acceptable as a fallback only if you can't move to Playwright export.

Rule 6: Use Playwright for PDF export — html2canvas/Ctrl+P are fallbacks.

Playwright page.pdf({width:'1920px', height:'1080px'}) is the only method that guarantees exact 16:9 page size regardless of user environment. Chrome's Ctrl+P UI ignores @page CSS when user picks Letter/Legal manually. Always create render-pdf.py alongside the deck HTML:

"""Render the deck to a 1920×1080 landscape PDF via Playwright."""
import asyncio
from pathlib import Path
from playwright.async_api import async_playwright

HERE = Path(__file__).parent
HTML = HERE / "deck.html"  # adjust to actual filename
OUT = Path.home() / "Downloads" / "deck.pdf"  # adjust


async def main():
    async with async_playwright() as pw:
        browser = await pw.chromium.launch()
        ctx = await browser.new_context(viewport={"width": 1920, "height": 1080})
        page = await ctx.new_page()
        await page.goto(HTML.as_uri(), wait_until="networkidle")
        await page.evaluate("document.fonts.ready")  # wait for web fonts (FOUT guard)
        await page.pdf(
            path=str(OUT), width="1920px", height="1080px",
            print_background=True,
            margin={"top":"0","right":"0","bottom":"0","left":"0"},
            prefer_css_page_size=False,
        )
        await browser.close()
    print(f"PDF written to {OUT} ({OUT.stat().st_size:,} bytes)")


asyncio.run(main())

Auto-open after creation/modification (MANDATORY): After running render-pdf.py, always chain start "" "<output.pdf>" so the user sees the result immediately. Same for the source HTML during iteration:

python render-pdf.py && start "" "%USERPROFILE%\Downloads\deck.pdf"

If the PDF is locked by an open viewer (PermissionError), fall back to V{N+1}.pdf naming (e.g., V4 → V5).

Print CSS still required for the rare Ctrl+P fallback path:

@media print {
  @page { size: 1920px 1080px; margin: 0; }
  html, body {
    background: #fff !important; margin: 0; padding: 0;
    -webkit-print-color-adjust: exact !important;
    print-color-adjust: exact !important;
  }
  .slide-nav, .download-section { display: none !important; }
  .deck { padding: 0 !important; }
  .slide {
    margin: 0 !important; box-shadow: none !important;
    page-break-after: always; page-break-inside: avoid; break-after: page;
    -webkit-print-color-adjust: exact !important;
    print-color-adjust: exact !important;
  }
  .slide:last-child { page-break-after: auto; break-after: auto; }
}

print-color-adjust:exact prevents Chrome's ink-saver from stripping accent colors. The html2canvas download button stays as a tertiary fallback in the download section.

Slide Dimensions

Each slide: width: 1920px; height: 1080px (16:9 ratio).

.slide {
  width: 1920px;
  height: 1080px;
  padding: 80px 100px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  box-sizing: border-box;
  overflow: hidden;
  position: relative;
}

position: relative is required so that absolutely-positioned children (slide-number, slide-footer) are positioned relative to the slide, not the viewport.

Font Size Minimums

Element	Size	Weight
Slide title	48px ~ 64px	800
Subtitle / section heading	36px ~ 44px	700
Body text	28px ~ 34px	400-500
Number callouts	72px ~ 120px	900
Caption / source	20px ~ 24px	400
Slide number	18px ~ 20px	400

These are MINIMUM sizes. If a slide has less content, scale UP the font sizes to fill the space rather than leaving empty areas.

Heading Letter Spacing

All headings (h1, h2) must have letter-spacing: 0.02em to prevent tight kerning at large sizes. Add this as a global CSS rule:

h1, h2 { letter-spacing: 0.02em; }

Spacing Rules

Slide padding: 80px ~ 100px
Content block gap: 40px+
Bullet point spacing: 32px+

Data Visualization

For stable PNG rendering, do NOT use external chart libraries (Chart.js, etc.).

Allowed methods:

Inline SVG
HTML/CSS div-based charts (width percentages, flexbox bars, etc.)

Recommended chart types (mix at least 2-3 per presentation):

Donut/pie charts (SVG)
Bar charts (CSS divs)
Comparison bars (side-by-side CSS)
Progress bars
Big number + label blocks
Timeline/process flow (CSS flexbox)

Checklist:

Numbers in the chart match the text
Percentages add up correctly
Sources are attributed
Each data slide focuses on one insight

Slide Numbering

All slides except Cover and Ending/CTA display a slide number. Position: bottom-right. Format: N / Total (e.g., 3 / 15).

Slide Navigator (Browser Preview)

Since 1920x1080 slides are larger than typical browser viewports, add a navigation helper at the top of the HTML:

<div class="slide-nav" id="slideNav">
  <span>Slide Navigator</span>
  <a href="#slide-1">1</a> <a href="#slide-2">2</a> ...
</div>

Each slide gets id="slide-N". The nav bar is fixed at top and is NOT inside any .slide element, so it's automatically excluded from PNG capture.

.slide-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: #333;
  color: #fff;
  padding: 8px 16px;
  z-index: 100000;
  display: flex;
  gap: 8px;
  align-items: center;
  font-family: var(--font-main);
  font-size: 14px;
}
.slide-nav a {
  color: #fff;
  background: #555;
  padding: 4px 10px;
  border-radius: 4px;
  text-decoration: none;
}
.slide-nav a:hover { background: #777; }

Year References

Always use the current year. Never hardcode a specific year.

Download Button (PDF)

Add a download section at the bottom of the HTML (after all slides, before </body>).

Libraries (EXACT CDN URLs — copy exactly, do NOT change versions):

<script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/html2canvas.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/jspdf.umd.min.js"></script>

CRITICAL:

Use html2canvas @1.4.1 + jsPDF @2.5.2. Access jsPDF via window.jspdf.jsPDF.
Do NOT use dom-to-image-more — it depends on viewport size and breaks in web/narrow

browser environments where viewport < 1920px.

html2canvas windowWidth: 1920 forces correct rendering regardless of viewport.
Use scale: 3 (not 2) for crisp text rasterization. Scale 2 produces visible

jagged edges on large serif/sans headings. Scale 3 ≈ laser-print quality.

Use JPEG quality: 0.95 (not 0.92). At scale 3, 0.92 adds mosquito noise

around text edges; 0.95 removes it while still keeping ~5–8MB total for 15 slides.

The rasterized button output is a fallback. The primary path must be **Ctrl+P /

Cmd+P → "Save as PDF"**, which preserves text as vectors. See Rule 6 and the Download Section template below — Ctrl+P must be shown prominently, button small.

Output is ALWAYS PDF, never PNG ZIP.

Complete download JS:

document.getElementById('downloadBtn').addEventListener('click', async function() {
  var btn = this;
  var status = document.getElementById('downloadStatus');
  btn.disabled = true;
  status.textContent = 'PDF 생성 중...';

  try {
    var jsPDF = window.jspdf.jsPDF;
    var pdf = new jsPDF({ orientation: 'landscape', unit: 'px', format: [1920, 1080], hotfixes: ['px_scaling'] });
    var slides = document.querySelectorAll('.slide');

    for (var i = 0; i < slides.length; i++) {
      status.textContent = '슬라이드 처리 중: ' + (i + 1) + '/' + slides.length;

      var canvas = await html2canvas(slides[i], {
        width: 1920,
        height: 1080,
        scale: 3,
        useCORS: true,
        allowTaint: true,
        scrollX: 0,
        scrollY: -window.scrollY,
        windowWidth: 1920,
        windowHeight: 1080
      });

      var imgData = canvas.toDataURL('image/jpeg', 0.95);
      if (i > 0) pdf.addPage([1920, 1080], 'landscape');
      pdf.addImage(imgData, 'JPEG', 0, 0, 1920, 1080);
    }

    status.textContent = 'PDF 저장 중...';
    pdf.save('{topic}-presentation.pdf');
    status.textContent = '✓ 다운로드 완료!';
  } catch (error) {
    console.error('Download failed:', error);
    status.textContent = '오류: ' + error.message;
  } finally {
    btn.disabled = false;
  }
});

Replace '{topic}-presentation.pdf' with the actual sanitized topic name (lowercase, hyphens, no special characters). Example: 'ai-marketing-presentation.pdf'

File naming: {topic}-presentation.pdf

Download Section UI (MANDATORY pattern):

The download area must prominently promote Ctrl/Cmd+P as the best-quality path. The html2canvas download button is shown as a smaller, de-emphasized fallback next to it. Never lead with the rasterized button.

<div class="download-section">
  <div class="best-option">
    <div class="best-label">★ Recommended — Best Quality</div>
    <div class="best-title">Press <kbd>Ctrl</kbd>+<kbd>P</kbd> → “Save as PDF”</div>
    <div class="best-note">Windows: <b>Ctrl+P</b> &nbsp;·&nbsp; Mac: <b>Cmd+P</b><br>Text stays vector-perfect. Use this option.</div>
  </div>
  <div class="fallback">
    <div class="fallback-label">Or — rasterized fallback</div>
    <button id="downloadBtn">Download PDF</button>
    <div id="downloadStatus"></div>
  </div>
</div>

.download-section {
  max-width: 1400px; margin: 60px auto 80px; text-align: center;
  color: #fff; font-family: var(--font-main, 'Inter', sans-serif);
  display: flex; gap: 24px; align-items: stretch; justify-content: center;
  flex-wrap: wrap;
}
.best-option {
  flex: 1 1 520px; max-width: 680px;
  background: #1a1a1a; border: 2px solid var(--accent, #3B82F6);
  padding: 36px 44px; border-radius: 10px;
  display: flex; flex-direction: column; justify-content: center;
}
.best-label {
  color: var(--accent, #3B82F6); font-size: 12px; font-weight: 700;
  letter-spacing: 4px; text-transform: uppercase; margin-bottom: 14px;
}
.best-title {
  color: #fff; font-size: 30px; font-weight: 600;
  margin-bottom: 10px; line-height: 1.2;
}
.best-title kbd {
  background: #fff; color: #000; padding: 6px 14px;
  border-radius: 6px; font-family: 'SF Mono', 'Monaco', monospace;
  font-size: 22px; margin: 0 4px; font-weight: 700;
  box-shadow: 0 2px 0 rgba(0, 0, 0, 0.35);
}
.best-note { color: #bbb; font-size: 14px; line-height: 1.5; }
.fallback {
  flex: 0 1 340px; opacity: 0.55;
  display: flex; flex-direction: column; justify-content: center;
  padding: 20px;
}
.fallback-label {
  color: #888; font-size: 11px; letter-spacing: 2px;
  text-transform: uppercase; margin-bottom: 12px; font-weight: 600;
}
#downloadBtn {
  background: transparent; color: #bbb; border: 1px solid #444;
  padding: 12px 28px; font-size: 13px; font-weight: 500;
  letter-spacing: 1.5px; text-transform: uppercase; cursor: pointer;
  border-radius: 4px;
}
#downloadBtn:hover { background: #333; color: #fff; border-color: #666; }
#downloadBtn:disabled { opacity: 0.5; cursor: not-allowed; }
#downloadStatus { margin-top: 14px; color: #888; font-size: 12px; }

The accent border on .best-option should use the theme's accent color so the Ctrl+P card feels native to the deck. Everything else stays neutral dark.

Step 4.5: Self-Review (MANDATORY before delivery)

Never deliver a deck without running self-review first. Capture each slide as a PNG via Playwright, Read each PNG to inspect visually, fix any issues found, then re-render. Only after all issues resolved → render PDF + auto-open + show user.

screenshot-slides.py (drop alongside render-pdf.py)

"""Capture each slide as PNG for self-review."""
import asyncio
from pathlib import Path
from playwright.async_api import async_playwright

HERE = Path(__file__).parent
HTML = HERE / "deck.html"  # adjust to actual filename
OUT_DIR = HERE / "_review"

async def main():
    OUT_DIR.mkdir(exist_ok=True)
    async with async_playwright() as pw:
        browser = await pw.chromium.launch()
        ctx = await browser.new_context(viewport={"width": 1920, "height": 1080})
        page = await ctx.new_page()
        await page.goto(HTML.as_uri(), wait_until="networkidle")
        await page.evaluate("document.fonts.ready")
        slides = await page.locator(".slide").all()
        for i, slide in enumerate(slides, 1):
            path = OUT_DIR / f"slide-{i:02d}.png"
            await slide.screenshot(path=str(path))
            print(path)
        await browser.close()

asyncio.run(main())

Review checklist for EACH slide

After running python screenshot-slides.py, Read each PNG and inspect for:

Line breaks (줄나눔) — words split mid-sentence in unintended places, "It was" orphaned to next line, Korean mid-word break. Fix with explicit <br> placement or font-size reduction.
Image cropping (이미지 잘림) — headshot off-frame, logo wall last logo cut on right, background-image stripped (if any remaining), photo without object-fit:cover. Fix with grid gap, max-width adjustment, or migrate to <img> tag.
Text overflow (글 잘림) — statement-line exceeding max-width, split slide right column truncated, cover-meta colliding with cover-sub (absolute positioning collision), footer wordmark cut. Fix with max-width adjustment, padding correction, or content trim.
Size mismatch (사이즈 안맞음) — content overflow beyond 1920×1080 (hidden by overflow:hidden), asymmetric split columns (gap+padding miscalculated), billboard-sized type (>180px H1), insufficient whitespace.
Brand consistency — if the deck belongs to a brand, check its brand guide (DESIGN.md) rules: correct fonts for emphasis/italic, accent colors only in allowed positions, wordmark reproduced exactly (including punctuation quirks).

Iteration loop

Found issues → list them concretely (slide N + issue) → fix CSS/copy → re-run screenshot script → re-Read affected slides → repeat until clean
All clear → python render-pdf.py && start "" "<output>.pdf"
Tell user what was caught & fixed:

> Self-review 1회 돌렸고 N개 이슈 잡아서 수정했어요: [list]. PDF 열었어요.

If genuinely zero issues:

Self-review 통과. PDF 열었어요.

Skip conditions (rare)

User explicitly says "빨리 보여줘", "review skip", "skip review"
Single-line copy edit on already-shown deck (and visual layout unchanged)
Non-visual changes (memory update, code-only refactor)

Step 5: Quality Check

Before delivering, verify:

Content

All data points are current and accurately represented
Text matches what was approved in Gate 2
Narrative arc flows logically from opening to closing
No slide has more than one key message

Design

Visual tone is consistent across all slides
Text density is comfortable (not wall-of-text)
Accent colors used sparingly, not overwhelming
Charts are easy to read at a glance
Font sizes meet minimums from the table above
Slide numbers are correct and sequential

Technical

HTML renders without errors
All slides are exactly 1920x1080
Download button functions correctly
No external image/resource dependencies (everything is inline)
Base64 images render correctly
Korean text wraps at word boundaries, not mid-character

Delivery

Save the final HTML to the outputs folder:

Output path: WARP/ppt-slides/{topic}/{topic}-presentation.html

Example: WARP/ppt-slides/ai-marketing/ai-marketing-presentation.html

Create the folder automatically if it doesn't exist. Then auto-open both the HTML (start "" <file>) and its folder in Explorer. The user previews with the slide navigator; the delivered PDF comes from render-pdf.py (auto-opened as well).