Update VT scan workflow

- Use v6.x for latest stable actions/checkout
- Use v6.x for latest stable Go version
- Add release line
- Scan on push using rules

Signed-off-by: nopeitsnothing <no@anonymousplanet.org>

.github/workflows/build-pdf.yml

@@ -31,7 +31,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v6
         with:
-          python-version: "3.12"
+          python-version: "3.13"
 
       - name: Install MkDocs Material
         run: pip install mkdocs-material
@@ -44,13 +44,22 @@ jobs:
       - name: Build PDF
         env:
           CI: true
-        run: python scripts/build_guide_pdf.py
+        run: python scripts/build_guide_pdf.py --both
 
       - name: Upload PDF artifact
         uses: actions/upload-artifact@v7
         with:
-          name: guide-pdf
-          path: export/guide.pdf
+          name: light-pdf
+          path: export/thgtoa.pdf
+          archive: false
+          if-no-files-found: error
+          retention-days: 90
+
+      - name: Upload PDF artifact (Dark Mode)
+        uses: actions/upload-artifact@v7
+        with:
+          name: dark-pdf
+          path: export/thgtoa-dark.pdf
           archive: false
           if-no-files-found: error
           retention-days: 90

.github/workflows/vt-scan.yml

@@ -0,0 +1,33 @@
+name: '🦠 VirusTotal Scan'
+
+on:
+    workflow_dispatch:
+    push:
+      branches:
+        - 'main'
+      tags:
+        - 'v*'
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+    steps:
+      - name: '📦 Checkout'
+        uses: actions/checkout@v6
+
+      - name: '📦 Set up Go'
+        uses: actions/setup-go@v6
+        with:
+            go-version: '1.26.2'
+      - run: go version
+
+      - name: '🦠 Scan PDF files using VT'
+        uses: crazy-max/ghaction-virustotal@v5
+        with:
+          vt_api_key: ${{ secrets.VT_API_KEY }}
+          update_release_body: true
+          files: |
+            ./export/thgtoa.pdf
+            ./export/thgtoa-dark.pdf

.gitignore

@@ -20,3 +20,4 @@ site/
 _site/
 _site_test/
 export/
+build/

CHANGELOG.md

@@ -7,11 +7,16 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- Refactored GitHub Actions workflow **Build PDF** (`scripts\build_guide_pdf.py`): now builds both light and dark mode PDFs (`export/thgtoa.pdf` and `export/thgtoa-dark.pdf` respectively).
+- Restored previous VT scans workflow **VirusTotal Scan** (`.github/workflows/vt-scan.yml`): submit files to VT for malware scanning. Links will be published on the site.
+
 ## [1.2.1] - 2026-04-11
 
 ### Added
 
-- GitHub Actions workflow **Build guide PDF** (`.github/workflows/build-pdf.yml`): installs Chromium on `ubuntu-latest`, runs `scripts/build_guide_pdf.py`, uploads `export/guide.pdf` as the `guide-pdf` artifact. Runs on `workflow_dispatch`, on pushes to `main` that touch docs or build inputs, and on matching pull requests.
+- GitHub Actions workflow **Build PDF** (`.github/workflows/build-pdf.yml`): installs Chromium on `ubuntu-latest`, runs `scripts/build_guide_pdf.py`, uploads `export/guide.pdf` as the `guide-pdf` artifact. Runs on `workflow_dispatch`, on pushes to `main` that touch docs or build inputs, and on matching pull requests.
 
 - `scripts/build_guide_pdf.py` to build the MkDocs site and render the guide to a single PDF (`export/guide.pdf` by default) using a Chromium-based browser (Chrome or Edge) headless print-to-PDF.
 - `docs/stylesheets/extra.css` and `extra_css` in `mkdocs.yml` for shared site styling.
@@ -23,7 +28,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Guide landing layout: wrap the opening block in `docs/guide/index.md` with a `guide-intro-lead` container so the logo and first sections share one layout context for web and print.
 - `.gitignore` to exclude local build outputs `export/`, `site/`, and `_site_test/`.
 - `scripts/build_guide_pdf.py`: when the `CI` environment variable is set, pass Chromium flags (`--no-sandbox`, `--disable-setuid-sandbox`, `--disable-dev-shm-usage`) so headless print works on typical CI images.
-- `README.md`: note the **Build guide PDF** GitHub Actions workflow and the `guide-pdf` artifact.
+- `README.md`: note the **Build PDF** GitHub Actions workflow and the `guide-pdf` artifact.
 
 ### Fixed
 

README.md

@@ -18,9 +18,9 @@ This guide is an open-source non-profit initiative, [licensed](LICENSE.html) und
   python scripts/build_guide_pdf.py
   ```
 
-  This runs `mkdocs build` (output defaults to `./site`), then uses **Google Chrome** or **Microsoft Edge** in headless mode to print `site/guide/index.html` to **`export/guide.pdf`** (images and styling preserved). If the site is already built: `python scripts/build_guide_pdf.py --skip-mkdocs`. Other options: `--site-dir`, `--pdf`, and `python scripts/build_guide_pdf.py --help`.
+  This runs `mkdocs build` (output defaults to `./site`), then uses **Google Chrome** or **Microsoft Edge** in headless mode to print `site/guide/index.html` to **`export/thgtoa.pdf`** (images and styling preserved). If the site is already built: `python scripts/build_guide_pdf.py --skip-mkdocs`. Other options: `--site-dir`, `--pdf`, and `python scripts/build_guide_pdf.py --help`.
 
-  On **GitHub Actions**, the [Build guide PDF](https://github.com/Anon-Planet/thgtoa/actions/workflows/build-pdf.yml) workflow does the same using Chromium on Ubuntu when you push to `main` or open a pull request that touches the guide or build inputs; download the **`guide-pdf`** artifact from a successful run. You can also run it manually (**Actions** → **Build guide PDF** → **Run workflow**).
+  On **GitHub Actions**, the [Build guide PDF](https://github.com/Anon-Planet/thgtoa/actions/workflows/build-pdf.yml) workflow does the same using Chromium on Ubuntu when you push to `main` or open a pull request that touches the guide or build inputs; download the **`thgtoa.pdf`** artifact from a successful run. You can also run it manually (**Actions** → **Build guide PDF** → **Run workflow**).
 - **OpenDocument (ODT):** not produced by this repository (previous hosted export removed).
 - **Raw Markdown (very large):** [docs/guide/index.md on GitHub](https://raw.githubusercontent.com/Anon-Planet/thgtoa/refs/heads/main/docs/guide/index.md)
 

docs/mirrors/index.md

@@ -27,9 +27,9 @@ schema:
 
 !!! Note "PDF export (single file)"
 
-    The guide is also available as a **PDF** (images and layout preserved). It is built automatically in GitHub Actions: open [**Build guide PDF**](https://github.com/Anon-Planet/thgtoa/actions/workflows/build-pdf.yml) on the [**thgtoa** source repository](https://github.com/Anon-Planet/thgtoa), pick a successful run, and download the **`guide-pdf`** artifact. You can start a fresh build anytime (**Actions** → **Build guide PDF** → **Run workflow**).
+    The guide is also available as a **PDF** (images and layout preserved). It is built automatically in GitHub Actions: open [**Build guide PDF**](https://github.com/Anon-Planet/thgtoa/actions/workflows/build-pdf.yml) on the [**source repository**](https://github.com/Anon-Planet/thgtoa), pick a successful run, and download the **`thgtoa`** and **`thgtoa-dark`** artifacts. You can start a fresh build anytime (**Actions** → **Build guide PDF** → **Run workflow**).
 
-    To produce the same file locally, clone the repository and run `python scripts/build_guide_pdf.py` (Python, [MkDocs Material](https://squidfunk.github.io/mkdocs-material/getting-started/), and **Google Chrome** or **Microsoft Edge** required). More detail is in the [repository README](https://github.com/Anon-Planet/thgtoa#ways-to-read-or-export-the-guide).
+    To produce the same file locally, clone the repository and run `python3 scripts/build_guide_pdf.py --both` (Python, [MkDocs Material](https://squidfunk.github.io/mkdocs-material/getting-started/), and **Google Chrome** or **Microsoft Edge** required). More detail is in the [repository README](https://github.com/Anon-Planet/thgtoa#ways-to-read-or-export-the-guide).
 
 !!! Note "Our official git mirrors"
 

docs/stylesheets/dark-extra.css

@@ -0,0 +1,130 @@
+/* Generate dark mode PDF of the HTML at guide/index.html */
+
+/*
+  DARK_MODE_PDF.CSS
+  Use this stylesheet when generating a PDF from HTML.
+*/
+
+:root {
+  /* Color Palette */
+  --bg-color: #121212;           /* Deep dark grey (easier on eyes than pure black) */
+  --text-primary: #e0e0e0;       /* Off-white for readability */
+  --text-secondary: #a0a0a0;     /* Grey for captions/metadata */
+  --accent-color: #bb86fc;       /* Light purple accent (optional) */
+  --border-color: #333333;       /* Subtle borders */
+
+  /* Fonts - System fonts ensure best rendering across PDF engines */
+  --font-main: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
+}
+
+/* --- RESET & BASE STYLES --- */
+* {
+  box-sizing: border-box;
+}
+
+body {
+  background-color: var(--bg-color);
+  color: var(--text-primary);
+  font-family: var(--font-main);
+  line-height: 1.6;
+  margin: 0;
+  padding: 0;
+}
+
+/* --- TYPOGRAPHY & HEADINGS --- */
+h1, h2, h3, h4, h5, h6 {
+  color: var(--text-primary);
+  font-weight: 700;
+  margin-top: 1.5em;
+  margin-bottom: 0.5em;
+}
+
+p {
+  margin-bottom: 1rem;
+  color: var(--text-secondary); /* Slightly dimmer text for body copy */
+}
+
+a {
+  color: var(--accent-color);
+  text-decoration: underline;
+}
+
+/* --- CONTAINER & LAYOUT --- */
+.container {
+  max-width: 800px;
+  margin: 40px auto;
+  padding: 20px;
+}
+
+/* Cards / Sections with dark backgrounds */
+.card {
+  background-color: #1e1e1e;
+  border: 1px solid var(--border-color);
+  border-radius: 8px;
+  padding: 20px;
+  margin-bottom: 20px;
+}
+
+/* --- TABLES (Common in PDFs) --- */
+table {
+  width: 100%;
+  border-collapse: collapse;
+  margin: 20px 0;
+  color: var(--text-primary);
+}
+
+th, td {
+  padding: 12px;
+  text-align: left;
+  border-bottom: 1px solid var(--border-color);
+}
+
+th {
+  background-color: #2c2c2c;
+  font-weight: bold;
+}
+
+tr:last-child td {
+  border-bottom: none;
+}
+
+/* --- IMAGES --- */
+img {
+  max-width: 100%;
+  height: auto;
+  display: block;
+  margin: 20px 0;
+  /* This ensures high contrast images don't get washed out */
+  filter: brightness(1.1);
+}
+
+/* --- CRITICAL FOR PDF GENERATORS --- */
+/* Forces the browser/PDF engine to print background colors and graphics */
+@media print {
+  @page {
+    size: A4; /* Change to 'Letter' if preferred */
+    margin: 20mm;
+  }
+
+  body {
+    background-color: var(--bg-color) !important;
+    color: var(--text-primary) !important;
+  }
+
+  .card, table th {
+    -webkit-print-color-adjust: exact !important; /* Chrome/Safari */
+    print-color-adjust: exact !important;          /* Firefox/Standard */
+    background-color: #1e1e1e !important;
+    color: var(--text-primary) !important;
+  }
+
+  /* Prevent page breaks in the middle of a sentence or card if possible */
+  .card {
+    break-inside: avoid;
+  }
+
+  /* Hide elements you don't want in PDF (like navigation bars) */
+  nav, footer, button {
+    display: none !important;
+  }
+}

mkdocs.yml

@@ -122,4 +122,4 @@ markdown_extensions:
       toc_depth: 3
 
 copyright: |
-  &copy; 2023-2025 <a href="https://anonymousplanet.org/"  target="_blank" rel="noopener">Anonymous Planet</a>
+  &copy; 2023-2026 <a href="https://anonymousplanet.org/"  target="_blank" rel="noopener">Anonymous Planet</a>

scripts/build_guide_pdf.py

@@ -1,161 +1,247 @@
-#!/usr/bin/env python3
-"""Build the MkDocs site, then render docs/guide/ to a single PDF via a Chromium-based browser.
-
-Uses headless Chrome/Edge print-to-PDF (embeds images). WeasyPrint-based mkdocs-with-pdf is
-omitted here because it needs GTK/Pango (awkward on Windows).
-
-Usage (from repo root):
-  python scripts/build_guide_pdf.py
-  python scripts/build_guide_pdf.py --site-dir build/html --pdf export/guide.pdf
-"""
-
-from __future__ import annotations
-
-import argparse
-import os
-import shutil
-import subprocess
-import sys
-import time
-from pathlib import Path
-
-
-def repo_root() -> Path:
-    return Path(__file__).resolve().parent.parent
-
-
-def find_chromium_executable() -> Path | None:
-    if sys.platform == "win32":
-        paths = [
-            Path(os.environ.get("PROGRAMFILES(X86)", "")) / "Microsoft/Edge/Application/msedge.exe",
-            Path(os.environ.get("LOCALAPPDATA", "")) / "Microsoft/Edge/Application/msedge.exe",
-            Path(os.environ.get("PROGRAMFILES", "")) / "Google/Chrome/Application/chrome.exe",
-            Path(os.environ.get("PROGRAMFILES(X86)", "")) / "Google/Chrome/Application/chrome.exe",
-            Path(os.environ.get("LOCALAPPDATA", "")) / "Google/Chrome/Application/chrome.exe",
-        ]
-        for p in paths:
-            if p.is_file():
-                return p
-        for name in ("chrome", "msedge"):
-            w = shutil.which(name)
-            if w:
-                return Path(w)
-    elif sys.platform == "darwin":
-        for p in (
-            "/Applications/Google Chrome.app/Contents/MacOS/Google Chrome",
-            "/Applications/Microsoft Edge.app/Contents/MacOS/Microsoft Edge",
-            "/Applications/Chromium.app/Contents/MacOS/Chromium",
-        ):
-            if os.path.isfile(p):
-                return Path(p)
-    for name in ("google-chrome-stable", "google-chrome", "chromium-browser", "chromium", "chrome"):
-        w = shutil.which(name)
-        if w:
-            return Path(w)
-    return None
-
-
-def run_mkdocs(site_dir: Path) -> None:
-    site_dir.mkdir(parents=True, exist_ok=True)
-    subprocess.run(
-        [sys.executable, "-m", "mkdocs", "build", "-d", str(site_dir)],
-        cwd=repo_root(),
-        check=True,
-    )
-
-
-def print_to_pdf(browser: Path, html_file: Path, pdf_out: Path) -> Path:
-    """Write PDF to ``pdf_out``. Uses a temp file first so an open ``guide.pdf`` on Windows
-    does not block the build: if the final path is locked, writes ``guide-new.pdf`` instead.
-    """
-    pdf_out.parent.mkdir(parents=True, exist_ok=True)
-    partial = pdf_out.parent / f".{pdf_out.name}.writing"
-    partial.unlink(missing_ok=True)
-
-    uri = html_file.resolve().as_uri()
-    # Chromium headless print; allow time for fonts/images on very large pages.
-    cmd = [str(browser)]
-    if os.environ.get("CI"):
-        # GitHub Actions / other CI runners often need these for Chromium to start.
-        cmd += [
-            "--no-sandbox",
-            "--disable-setuid-sandbox",
-            "--disable-dev-shm-usage",
-        ]
-    cmd += [
-        "--headless=new",
-        "--disable-gpu",
-        "--no-pdf-header-footer",
-        f"--print-to-pdf={partial.resolve()}",
-        uri,
-    ]
-    subprocess.run(cmd, check=True, timeout=600)
-    deadline = time.time() + 120
-    while time.time() < deadline:
-        if partial.exists() and partial.stat().st_size > 0:
-            break
-        time.sleep(0.25)
-    else:
-        partial.unlink(missing_ok=True)
-        raise RuntimeError(f"PDF was not written to {partial}")
-
-    try:
-        if pdf_out.exists():
-            pdf_out.unlink()
-    except PermissionError:
-        fallback = pdf_out.with_name(f"{pdf_out.stem}-new{pdf_out.suffix}")
-        fallback.unlink(missing_ok=True)
-        partial.replace(fallback)
-        return fallback
-
-    partial.replace(pdf_out)
-    return pdf_out
-
-
-def main() -> int:
-    root = repo_root()
-    ap = argparse.ArgumentParser(description="Build MkDocs + single-page guide PDF.")
-    ap.add_argument(
-        "--site-dir",
-        type=Path,
-        default=root / "site",
-        help="MkDocs output directory (default: ./site)",
-    )
-    ap.add_argument(
-        "--pdf",
-        type=Path,
-        default=root / "export" / "guide.pdf",
-        help="Output PDF path (default: ./export/guide.pdf)",
-    )
-    ap.add_argument("--skip-mkdocs", action="store_true", help="Reuse existing site dir; only run print-to-pdf.")
-    args = ap.parse_args()
-
-    guide_html = args.site_dir / "guide" / "index.html"
-    if not args.skip_mkdocs:
-        run_mkdocs(args.site_dir)
-    if not guide_html.is_file():
-        print(f"Missing {guide_html}; run without --skip-mkdocs first.", file=sys.stderr)
-        return 1
-
-    browser = find_chromium_executable()
-    if not browser:
-        print(
-            "No Chromium-based browser found (Chrome, Edge, or Chromium). "
-            "Install Google Chrome or Microsoft Edge, or add Chromium to PATH.",
-            file=sys.stderr,
-        )
-        return 1
-
-    out = print_to_pdf(browser, guide_html, args.pdf)
-    size_kb = out.stat().st_size // 1024
-    print(f"Wrote {out.resolve()} ({size_kb} KiB)")
-    if out.resolve() != args.pdf.resolve():
-        print(
-            f"Note: {args.pdf.name} was in use; close it and rename or replace with the file above.",
-            file=sys.stderr,
-        )
-    return 0
-
-
-if __name__ == "__main__":
-    raise SystemExit(main())
+#!/usr/bin/env python3
+"""Extended version of build_guide_pdf.py with dark mode support.
+
+This script builds both light and dark mode MkDocs site, then renders docs/guide/ to single PDFs via Chromium.
+
+Usage:
+  python scripts/build_guide_pdf_extended.py                    # Generate light mode PDF only
+  python scripts/build_guide_pdf_extended.py --dark-mode        # Generate dark mode PDF only
+  python scripts/build_guide_pdf_extended.py --both             # Generate both light and dark mode PDFs
+
+Examples:
+  python scripts/build_guide_pdf_extended.py --site-dir build/html --pdf-light export/thgtoa.pdf
+  python scripts/build_guide_pdf_extended.py --dark-mode --pdf-dark export/thgtoa-dark.pdf
+"""
+
+from __future__ import annotations
+
+import argparse
+import os
+import shutil
+import subprocess
+import sys
+import time
+from pathlib import Path
+
+
+def repo_root() -> Path:
+    return Path(__file__).resolve().parent.parent
+
+
+def find_chromium_executable() -> Path | None:
+    if sys.platform == "win32":
+        paths = [
+            Path(os.environ.get("PROGRAMFILES(X86)", "")) / "Microsoft/Edge/Application/msedge.exe",
+            Path(os.environ.get("LOCALAPPDATA", "")) / "Microsoft/Edge/Application/msedge.exe",
+            Path(os.environ.get("PROGRAMFILES", "")) / "Google/Chrome/Application/chrome.exe",
+            Path(os.environ.get("PROGRAMFILES(X86)", "")) / "Google/Chrome/Application/chrome.exe",
+            Path(os.environ.get("LOCALAPPDATA", "")) / "Google/Chrome/Application/chrome.exe",
+        ]
+        for p in paths:
+            if p.is_file():
+                return p
+        for name in ("chrome", "msedge"):
+            w = shutil.which(name)
+            if w:
+                return Path(w)
+    elif sys.platform == "darwin":
+        for p in (
+            "/Applications/Google Chrome.app/Contents/MacOS/Google Chrome",
+            "/Applications/Microsoft Edge.app/Contents/MacOS/Microsoft Edge",
+            "/Applications/Chromium.app/Contents/MacOS/Chromium",
+        ):
+            if os.path.isfile(p):
+                return Path(p)
+    for name in ("google-chrome-stable", "google-chrome", "chromium-browser", "chromium", "chrome"):
+        w = shutil.which(name)
+        if w:
+            return Path(w)
+    return None
+
+
+def run_mkdocs(site_dir: Path) -> None:
+    site_dir.mkdir(parents=True, exist_ok=True)
+    subprocess.run(
+        [sys.executable, "-m", "mkdocs", "build", "-d", str(site_dir)],
+        cwd=repo_root(),
+        check=True,
+    )
+
+
+def print_to_pdf(browser: Path, html_file: Path, pdf_out: Path, dark_mode: bool = False) -> Path:
+    """Write PDF to ``pdf_out``. Uses a temp file first so an open ``guide.pdf`` on Windows
+    does not block the build: if the final path is locked, writes ``guide-new.pdf`` instead.
+
+    Args:
+        browser: Path to Chromium executable
+        html_file: Path to HTML file to convert
+        pdf_out: Output PDF path
+        dark_mode: If True, use dark mode color scheme via --prefers-color-scheme flag
+    """
+    pdf_out.parent.mkdir(parents=True, exist_ok=True)
+    partial = pdf_out.parent / f".{pdf_out.name}.writing"
+    partial.unlink(missing_ok=True)
+
+    uri = html_file.resolve().as_uri()
+
+    # Chromium headless print; allow time for fonts/images on very large pages.
+    cmd = [str(browser)]
+    if os.environ.get("CI"):
+        # GitHub Actions / other CI runners often need these for Chromium to start.
+        cmd += [
+            "--no-sandbox",
+            "--disable-setuid-sandbox",
+            "--disable-dev-shm-usage",
+        ]
+
+    cmd += [
+        "--headless=new",
+        "--disable-gpu",
+        "--no-pdf-header-footer",
+    ]
+
+    # Add dark mode preference if requested
+    if dark_mode:
+        cmd.append("--prefers-color-scheme=dark")
+
+    cmd += [
+        f"--print-to-pdf={partial.resolve()}",
+        uri,
+    ]
+
+    subprocess.run(cmd, check=True, timeout=600)
+    deadline = time.time() + 120
+    while time.time() < deadline:
+        if partial.exists() and partial.stat().st_size > 0:
+            break
+        time.sleep(0.25)
+    else:
+        partial.unlink(missing_ok=True)
+        raise RuntimeError(f"PDF was not written to {partial}")
+
+    try:
+        if pdf_out.exists():
+            pdf_out.unlink()
+    except PermissionError:
+        fallback = pdf_out.with_name(f"{pdf_out.stem}-new{pdf_out.suffix}")
+        fallback.unlink(missing_ok=True)
+        partial.replace(fallback)
+        return fallback
+
+    partial.replace(pdf_out)
+    return pdf_out
+
+
+def generate_dark_mode_html(html_file: Path, output_file: Path, dark_css_path: Path) -> None:
+    """Create a temporary HTML file with dark mode stylesheet applied.
+
+    This is used when we need to force dark mode rendering via CSS rather than browser flags.
+    """
+    try:
+        from bs4 import BeautifulSoup
+
+        # Read the original HTML
+        html_content = html_file.read_text(encoding='utf-8')
+        soup = BeautifulSoup(html_content, 'html.parser')
+
+        # Add dark mode stylesheet link if not present
+        existing_links = [link.get('href', '') for link in soup.find_all('link', rel='stylesheet')]
+        if not any(dark_css_path.name in link for link in existing_links):
+            head = soup.head or soup.new_tag('head')
+            link_tag = soup.new_tag('link', rel='stylesheet', href=str(dark_css_path))
+            if soup.head:
+                soup.head.append(link_tag)
+            else:
+                # Create a new head section
+                new_head = soup.new_tag('head')
+                new_head.append(link_tag)
+                soup.insert(0, new_head)
+
+        # Write the modified HTML
+        output_file.parent.mkdir(parents=True, exist_ok=True)
+        output_file.write_text(str(soup), encoding='utf-8')
+    except ImportError:
+        print("BeautifulSoup not available. Skipping CSS injection.")
+
+
+def main() -> int:
+    root = repo_root()
+    ap = argparse.ArgumentParser(description="Build MkDocs + single-page guide PDF (light and/or dark mode).")
+    ap.add_argument(
+        "--site-dir",
+        type=Path,
+        default=root / "build" / "html",
+        help="MkDocs output directory (default: ./build/html)",
+    )
+    ap.add_argument(
+        "--pdf-light",
+        type=Path,
+        default=root / "export" / "thgtoa.pdf",
+        help="Output PDF path for light mode (default: ./export/guide.pdf)",
+    )
+    ap.add_argument(
+        "--pdf-dark",
+        type=Path,
+        default=root / "export" / "thgtoa-dark.pdf",
+        help="Output PDF path for dark mode (default: ./export/guide-dark.pdf)",
+    )
+    ap.add_argument("--skip-mkdocs", action="store_true", help="Reuse existing site dir; only run print-to-pdf.")
+    ap.add_argument("--dark-mode", action="store_true", help="Generate dark mode PDF only")
+    ap.add_argument("--both", action="store_true", help="Generate both light and dark mode PDFs")
+    args = ap.parse_args()
+
+    # Determine which modes to generate
+    if args.dark_mode:
+        modes = ["dark"]
+    elif args.both:
+        modes = ["light", "dark"]
+    else:
+        modes = ["light"]
+
+    guide_html = args.site_dir / "guide" / "index.html"
+
+    if not args.skip_mkdocs or any(mode == "light" for mode in modes):
+        run_mkdocs(args.site_dir)
+
+    if not guide_html.is_file():
+        print(f"Missing {guide_html}; run without --skip-mkdocs first.", file=sys.stderr)
+        return 1
+
+    browser = find_chromium_executable()
+    if not browser:
+        print(
+            "No Chromium-based browser found (Chrome, Edge, or Chromium). "
+            "Install Google Chrome or Microsoft Edge, or add Chromium to PATH.",
+            file=sys.stderr,
+        )
+        return 1
+
+    dark_css_path = root / "docs" / "stylesheets" / "dark-extra.css"
+
+    # Generate light mode PDF (default)
+    if "light" in modes:
+        out_light = print_to_pdf(browser, guide_html, args.pdf_light, dark_mode=False)
+        size_kb = out_light.stat().st_size // 1024
+        print(f"Wrote {out_light.resolve()} ({size_kb} KiB) [Light Mode]")
+        if out_light.resolve() != args.pdf_light.resolve():
+            print(
+                f"Note: {args.pdf_light.name} was in use; close it and rename or replace with the file above.",
+                file=sys.stderr,
+            )
+
+    # Generate dark mode PDF
+    if "dark" in modes:
+        out_dark = print_to_pdf(browser, guide_html, args.pdf_dark, dark_mode=True)
+        size_kb = out_dark.stat().st_size // 1024
+        print(f"Wrote {out_dark.resolve()} ({size_kb} KiB) [Dark Mode]")
+        if out_dark.resolve() != args.pdf_dark.resolve():
+            print(
+                f"Note: {args.pdf_dark.name} was in use; close it and rename or replace with the file above.",
+                file=sys.stderr,
+            )
+
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())