pdf-creator

name

pdf-creator

description

Convert markdown files to professional PDF documents with proper Chinese font support, theme system, and visual self-check. Use whenever the user asks to create PDFs, convert markdown to PDF, generate printable documents, or needs documents formatted for print or mobile reading. This skill MUST be used instead of manual pandoc/Chrome invocations — it handles CJK typography, Chrome header/footer suppression, and mandatory visual verification that manual approaches miss. **Scope: markdown → PDF only.** For Word (.docx) output use `minimax-docx`; this skill does not produce docx and the two pipelines are intentionally orthogonal.

PDF Creator

Create professional PDF documents from markdown with Chinese font support and theme system.

Quick Start

# Default theme (formal: Songti SC + black/grey, A4 print)
uv run --with weasyprint scripts/md_to_pdf.py input.md output.pdf

# Warm theme (training: PingFang SC + terra cotta)
uv run --with weasyprint scripts/md_to_pdf.py input.md --theme warm-terra

# Mobile theme (narrow page, large font — for phone reading / WeChat sharing)
uv run --with weasyprint scripts/md_to_pdf.py input.md --theme mobile

# Batch convert all markdown files with a specific theme
uv run --with weasyprint scripts/batch_convert.py *.md --theme warm-terra --no-preview

# No weasyprint? Use Chrome backend (auto-detected if weasyprint unavailable)
python scripts/md_to_pdf.py input.md --theme warm-terra --backend chrome

# List available themes
python scripts/md_to_pdf.py --list-themes dummy.md

Themes

Stored in themes/*.css. Each theme is a standalone CSS file.

Theme	Page Size	Font	Color	Best for
default	A4	Songti SC + Heiti SC	Black/grey	Legal docs, contracts, formal reports
cjk-auto	A4	Songti SC + Heiti SC	Black/grey	Tables with uneven column content (course schedules, itemized lists)
warm-terra	A4	PingFang SC	Terra cotta (#d97756) + warm neutrals	Course outlines, training materials, workshops
mobile	148mm × 210mm	PingFang SC	Terra cotta + warm neutrals	Phone reading, WeChat sharing, on-the-go reference

To create a new theme: copy themes/default.css, modify, save as themes/your-theme.css.

Print vs Mobile: Choose the Right Theme

Scenario	Recommended Theme	Why
Print on A4 paper, handouts, contracts	default	Standard page size, formal typography
Training materials, course outlines	warm-terra	Warm accent color, readable for workshop contexts
Send via WeChat, read on phone	mobile	Narrow page (148mm), 15px font, 1.9 line-height — comfortable on small screens
Both print AND mobile needed	Run twice with different themes	The skill is fast; generate both versions

Decision rule: If the user does not specify, default to warm-terra for training/course content and default for formal documents. Ask "是否需要手机版？" only when the output channel is unclear.

Backends

The script auto-detects the best available backend based on content:

• CJK content detected → auto-selects Chrome (weasyprint subset-embeds PingFang SC as CID Type 0C OpenType, which macOS Preview / Adobe Reader fail to render — appears as garbled text on recipient devices even though it looks fine in Chrome's PDF viewer)
• Non-CJK content → auto-selects weasyprint (faster, no browser startup)

Backend	Install	Pros	Cons
weasyprint	pip install weasyprint	Precise CSS rendering, no browser needed	CJK font embedding bug on some readers
chrome	Google Chrome installed	Zero Python deps, reliable CJK rendering	Larger binary, slightly less CSS control

Override with --backend chrome or --backend weasyprint.

Batch Convert

# Default theme, same directory
uv run --with weasyprint scripts/batch_convert.py *.md

# Specific theme, output directory, skip previews for speed
uv run --with weasyprint scripts/batch_convert.py *.md --theme warm-terra --output-dir ./pdfs --no-preview

# Mobile theme for phone reading
uv run --with weasyprint scripts/batch_convert.py *.md --theme mobile --output-dir ./mobile-pdfs --no-preview

Anti-Pattern: Do NOT Manually Invoke pandoc + Chrome

Why this skill exists: Manual pandoc input.md -o out.html + chrome --headless --print-to-pdf workflows silently fail in ways that are hard to detect:

Manual Step	What Goes Wrong	This Skill Fixes
pandoc -o out.html	No CJK-aware CSS → boxes/blanks for Chinese	Injects CJK font stack + typography patch
Chrome --print-to-pdf	Default header/footer appears (filename, date, URL, page numbers)	Passes --no-pdf-header-footer
No post-render check	"Exit code 0" assumed success; rendering bugs hidden	Auto-generates per-page PNG previews + typography lint
No theme system	One-size-fits-all; phone reading impossible	Three curated themes (default / warm-terra / mobile)
batch_convert.py missing	Writing ad-hoc loops, inconsistent flags	Built-in batch mode with --theme support

Rule: When the user asks for PDF conversion, ALWAYS use this skill. Never bypass it with manual pandoc/Chrome commands.

Troubleshooting

Chinese characters display as boxes: Ensure Chinese fonts are installed (Songti SC, PingFang SC, etc.)

weasyprint import error: Run with uv run --with weasyprint or use --backend chrome instead.

CJK text in code blocks garbled (weasyprint): The script auto-detects code blocks containing Chinese/Japanese/Korean characters and converts them to styled divs with CJK-capable fonts. If you still see issues, use --backend chrome which has native CJK support. Alternatively, convert code blocks to markdown tables before generating the PDF.

Chrome header/footer appearing: The script passes --no-pdf-header-footer. If it still appears, your Chrome version may not support this flag — update Chrome. Note: If you bypassed this skill and used manual Chrome headless, this is the first symptom — see "Anti-Pattern" section above.

Inline code with mixed CJK + ASCII shows blanks in macOS Preview (e.g. `Terminal/终端` renders only Terminal/ with the CJK part missing): weasyprint subset-embeds PingFang SC as OpenType (CID Type 0C), which strict PDF readers (macOS Preview / Adobe Reader) fail to render. Chrome's PDF viewer falls back automatically and hides the bug. Fix is in the default theme: code font-family chain prioritizes CID TrueType CJK fonts (Songti SC / Heiti SC) before OpenType ones (PingFang SC). To verify: pdfplumber + check font['fontname'] of CJK chars — if any references PingFang-SC (CID Type 0C OT), readers will likely fail. Reorder font chain to put CID TrueType first.

Table column 1 with short label gets mid-broken (e.g. 4/28（周|二）下|午): pandoc auto-emits <colgroup><col style="width:X%"> from dash counts in the markdown separator row. For | ----- | --- | --- | -------- | (uneven dash widths), pandoc allocates col 1 ~17% — too narrow for a 9-char CJK label. Inline style="" beats external CSS at equal specificity, so td:first-child { width:... } is silently shadowed. Fix is in default theme: table colgroup col { width: auto !important } neutralizes pandoc's hint, letting table-layout: fixed distribute equally (25% per column for a 4-col table). To verify: pandoc input.md -t html | grep colgroup — if it shows <col style="width:X%">, the bug applies. Scope: the neutralizer lives only in default.css; warm-terra and mobile themes use different strategies (nowrap on th/td with last-child wrap, and full-flow wrap respectively) and intentionally omit it. The neutralizer is locked in by scripts/tests/test_cjk_tables.py::test_default_theme_neutralizes_pandoc_colgroup_hint.

Visual Self-Check (MANDATORY — Do Not Skip)

This is not optional. After every PDF generation, the script automatically:

1. Converts each page to PNG via pdftoppm (poppler-utils) into a <pdf-name>/ subdirectory under the system temp dir (NOT next to the PDF — previews are a throwaway self-check artifact and must never linger in your working tree / git repo). The exact path is printed after the run as Previews: <path>/page-NN.png
2. Prints a structured self-check checklist reminding the caller to visually inspect each page
3. Runs typography lint to detect CJK line-break anti-patterns

Why mandatory: "PDF generated cleanly" ≠ "rendering matches markdown intent". Common silent failures include:

• Paragraphs collapsing into one (CommonMark soft-break on consecutive non-blank lines)
• Tables overflowing page margins
• Missing CJK / emoji glyphs
• Code block garbling
• Chrome default headers/footers (if bypassed this skill)

Workflow: After running the script, Read each page-NN.png at the printed Previews: path and verify against the markdown source. If anything renders differently from intent, fix the markdown (use - real lists instead of pseudo-lists, insert blank lines, restructure tables) and rerun. The script does NOT silently "fix" non-standard markdown — that would mask the signal that the source is wrong, causing the same markdown to render incorrectly in other processors (Obsidian, GitHub, VS Code preview).

Disable with --no-preview for batch / non-interactive runs:

python scripts/md_to_pdf.py input.md output.pdf --no-preview

Requires pdftoppm (brew install poppler on macOS). If not installed, the script logs a hint and skips preview generation but still produces the PDF.

CJK Typography (default behavior)

The script applies two layers of CJK-aware processing automatically — without modifying the user's markdown source or theme CSS files:

Layer 1: CSS patch (auto-injected, fixes ~80% of cases)

_load_theme() appends a CJK typography CSS patch to the loaded theme CSS. The patch:

• table { table-layout: fixed; width: 100% } — equal column widths prevent weasyprint auto-layout from squeezing one column to ~10% width when an adjacent column has 5x more content
• td, th { word-break: keep-all; overflow-wrap: normal; line-break: strict } — don't slice CJK characters apart. The deliberate trade-off encoded by overflow-wrap: normal (not break-word) is to let content overflow slightly rather than fall back to mid-token breaks — rationale documented in md_to_pdf.py L109-146 inline comments and locked in by scripts/tests/test_cjk_tables.py
• th { white-space: nowrap } — short headers stay one line for predictable column widths

This silently fixes the most common anti-pattern (cell content forcibly wrapped between CJK characters producing single-char-only lines), without touching the user's source. The user's theme CSS file on disk is never modified.

Layer 2: Typography lint (post-render detection, catches the rest)

After PDF generation, the script runs pdftotext -layout per page and scans for known CJK anti-patterns per "中文文案排版指北" (Chinese typography style guide):

• Single CJK character alone on a line (cell still too narrow even after Layer 1)
• Line ending with （ followed by content next line (broken bracket pair)
• Line starting with ） (broken from previous bracket pair)
• Short line ending with mid-thought punctuation 、，；：

Findings are printed to stderr with page+line locations. They are warnings, not errors — PDF still generates. The author sees the finding and decides:

1. Accept (e.g. one orphan char in a long doc may be acceptable)
2. Shorten the offending cell content to fit the column width
3. Restructure (e.g. move long content into a paragraph below the table)

Why not silently auto-fix everything?

Layer 2 deliberately does NOT modify the markdown. Per CLAUDE.md "禁止隐式行为" rule: silently rewriting non-standard markdown (e.g. expanding pseudo-lists into real lists) would mask the signal that the source is wrong, causing the same markdown to render incorrectly in other processors. Layer 1 is acceptable because it patches rendering behavior for already-standard markdown (a standard table that weasyprint happens to render imperfectly for CJK), not the markdown source itself.

Known limitations

When a single cell's content is just slightly longer than the available column width (e.g. 10 CJK chars in a 9-char-wide cell after equal split), weasyprint will fall back to forced break despite keep-all. Layer 1 cannot fix this — Layer 2 will catch it and prompt the author to shorten cell content or restructure.