From a2455c3f8a721521941b29d69d71982ec9b5801e Mon Sep 17 00:00:00 2001
From: Amit Haridas <amit.wh@gmail.com>
Date: Sat, 5 Sep 2026 23:59:53 +0530
Subject: [PATCH] feat(export): themable PDF/Word exports; Windows CI green
 (v4.7.1)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Export themes:
- Six presets in the export dialog (basic + advanced modes) for PDF/DOCX:
  Default, Modern, Classic, Sepia, Minimal, Elegant
- PDF: LaTeX header (xcolor/titlesec) recolors headings, adds section
  rules and colored links — core-TeX packages only, hex-literal only
  (no injection surface)
- DOCX: styles.xml surgery recolors Heading1-6/Title/Subtitle/Hyperlink
  and swaps heading/body fonts; verified end-to-end against a real
  pandoc-produced docx
- Themes ride along in export presets (unknown ids fall back to Default)

Windows CI fixes:
- pdfjs standardFontDataUrl now a file:// URL (backslash paths failed
  pdfjs's trailing-slash validation, breaking extractText/extractImages)
- sharp temp cleanup EPERM retries; path-separator assertions; pdfjs
  test timeouts raised; batch suite testTimeout 30s

648/648 tests green; 4.7.1 linux+win artifacts rebuilt.
---
 README.md                             |   1 +
 UPDATES.md                            |  30 ++++
 src/index.html                        |   7 +
 src/main.js                           |  24 +++
 src/main/ExportThemes.js              | 248 ++++++++++++++++++++++++++
 src/renderer.js                       |  26 +++
 src/renderer/export-presets.js        |  15 ++
 tests/main/ExportThemes.test.js       | 181 +++++++++++++++++++
 tests/main/ImageOperations.test.js    |  10 +-
 tests/main/PDFBatchOperations.test.js |   1 +
 tests/main/PDFOperations.test.js      |  77 ++++----
 tests/monospace-font-config.test.js   |   5 +-
 12 files changed, 590 insertions(+), 35 deletions(-)
 create mode 100644 src/main/ExportThemes.js
 create mode 100644 tests/main/ExportThemes.test.js

diff --git a/README.md b/README.md
index de494c5..307f846 100644
--- a/README.md
+++ b/README.md
@@ -47,6 +47,7 @@ A powerful cross-platform Markdown editor and document converter powered by Pand
 - **EPUB** - E-book format
 - **LaTeX** - Academic document format
 - **RTF** - Rich Text Format
+- **Export themes** - Five visual styles (Modern, Classic, Sepia, Minimal, Elegant) for PDF and Word exports — recolored headings, links, and fonts
 
 ### Advanced Features
 - **Custom headers & footers** - Add headers/footers to exports with dynamic fields
diff --git a/UPDATES.md b/UPDATES.md
index a2d4bc3..e2fdca2 100644
--- a/UPDATES.md
+++ b/UPDATES.md
@@ -1,5 +1,35 @@
 # PanConverter - Updates & Changelog
 
+## Version 4.7.1 (2026-09-05)
+
+### New: Export Themes (Word + PDF)
+- Theme picker in the export dialog (basic and advanced mode) for PDF and DOCX:
+  **Default (Pandoc), Modern, Classic, Sepia, Minimal, Elegant**
+- PDF: LaTeX header recolors/reformats headings + links (xcolor/titlesec,
+  core-TeX packages only); DOCX: styles.xml surgery recolors Heading1-6/Title/
+  Subtitle/Hyperlink and swaps heading/body fonts
+- Themes persist in export presets; unknown ids in old presets fall back to
+  Default instead of failing the export
+
+### Branding
+- New M↓ brand identity: app icons, favicons, tray icon, welcome mark,
+  README wordmark (vector kit in assets/markdown-converter-assets/)
+
+### Fixes
+- **Windows**: pdfjs text/image extraction failed on Windows —
+  standardFontDataUrl is now a proper file:// URL (raw backslash paths
+  failed pdfjs's trailing-slash URL validation)
+- **Windows**: sharp temp-file cleanup (EPERM retry), path-separator test
+  assertions, and pdfjs test timeouts fixed — the Windows CI job is green
+- FiraCode tooling downloads pinned to the immutable 6.2 release;
+  .gitattributes stops CRLF checkout rewriting hash-pinned files
+- macOS pandoc extractor locates the binary in the archive (layout changed)
+- Packaged apps resolve bundled pandoc/markitdown next to the executable
+  (resourcesPath lookup was wrong since 4.5 — packaged builds silently used
+  system pandoc)
+
+---
+
 ## Version 4.7.0 (2026-09-05)
 
 ### Bundling & Legal Compliance
diff --git a/src/index.html b/src/index.html
index c1b01d3..91ed50c 100644
--- a/src/index.html
+++ b/src/index.html
@@ -582,6 +582,13 @@
                   <option value="landscape">Landscape</option>
                 </select>
               </div>
+              <!-- Export theme (PDF / DOCX): heading & link styling presets -->
+              <div class="form-row" id="export-theme-row" style="display: none">
+                <label for="export-theme">Theme:</label>
+                <select id="export-theme">
+                  <!-- Populated from src/main/ExportThemes.js at dialog open -->
+                </select>
+              </div>
               <div id="custom-page-size" class="form-row" style="display: none">
                 <label>Custom Size:</label>
                 <input
diff --git a/src/main.js b/src/main.js
index 3434a7c..41fbd22 100644
--- a/src/main.js
+++ b/src/main.js
@@ -2973,6 +2973,20 @@ function performExportWithOptions(format, options) {
         pandocArgs.push(`--include-in-header=${monoHeader}`);
         pandocArgs.push('--highlight-style=tango');
 
+        // Export theme: recolored headings/links via a LaTeX header
+        if (options.theme && options.theme !== 'default') {
+          const ExportThemes = require('./main/ExportThemes');
+          const themeTex = ExportThemes.buildLatexThemeHeader(options.theme);
+          if (themeTex) {
+            const themeFile = path.join(
+              require('os').tmpdir(),
+              `theme_${Date.now()}_${process.pid}.tex`
+            );
+            fs.writeFileSync(themeFile, themeTex, 'utf-8');
+            pandocArgs.push(`--include-in-header=${themeFile}`);
+          }
+        }
+
         // Add header/footer if enabled
         if (headerFooterSettings.enabled) {
           const filename = currentFile
@@ -3025,6 +3039,16 @@ function performExportWithOptions(format, options) {
         });
       } else if (format === 'docx') {
         exportWithPandoc(pandocArgs, outputFile, format, async () => {
+          // Export theme: recolor headings/links + swap fonts in styles.xml
+          if (options.theme && options.theme !== 'default') {
+            try {
+              const ExportThemes = require('./main/ExportThemes');
+              ExportThemes.applyDocxTheme(outputFile, options.theme);
+            } catch (themeErr) {
+              if (typeof console !== 'undefined')
+                console.warn('[docx] theme apply failed:', themeErr.message);
+            }
+          }
           // Embed the active monospace TTF into the DOCX so code blocks render in
           // JetBrains Mono / Fira Code regardless of the viewer's installed fonts.
           try {
diff --git a/src/main/ExportThemes.js b/src/main/ExportThemes.js
new file mode 100644
index 0000000..0b77a54
--- /dev/null
+++ b/src/main/ExportThemes.js
@@ -0,0 +1,248 @@
+/**
+ * Export themes — named visual styles for PDF (LaTeX) and Word (DOCX) export.
+ *
+ * One definition drives both targets:
+ *   - PDF: a LaTeX header (xcolor + titlesec) recoloring/reformatting
+ *     headings and links, appended via --include-in-header next to the
+ *     existing monospace-font header. Only packages shipped in every TeX
+ *     distribution are used (xcolor, titlesec, helvet — all in scheme-basic).
+ *   - DOCX: a styles.xml patch (PizZip surgery, same technique as
+ *     OdtStyling/DocxFontEmbedder) recoloring Heading1-6/Title/Hyperlink
+ *     styles and swapping heading fonts.
+ *
+ * "default" means unstyled (pandoc's native look) and is the fallback for
+ * unknown ids — a stale theme id in saved presets must never fail an export.
+ *
+ * @module ExportThemes
+ */
+
+const THEMES = {
+  default: {
+    label: 'Default (Pandoc)',
+    description: "Pandoc's native styling",
+    // No patches — used as the safe fallback
+    pdf: null,
+    docx: null,
+  },
+  modern: {
+    label: 'Modern',
+    description: 'Sans-serif blue headings, teal links, airy section rules',
+    pdf: {
+      headingColor: '1E4FD8', // strong blue
+      linkColor: '0E7490', // teal
+      ruleColor: 'C7D2FE', // light indigo rule under sections
+      sansHeadings: true, // \usepackage{helvet} + \sanstitle (kp-fonts-free?)
+      sectionRule: true,
+    },
+    docx: {
+      headingColor: '1E4FD8',
+      linkColor: '0E7490',
+      headingFont: 'Calibri',
+      bodyFont: 'Calibri',
+    },
+  },
+  classic: {
+    label: 'Classic',
+    description: 'Serif type, deep-navy headings, burgundy links',
+    pdf: {
+      headingColor: '1F3A5F',
+      linkColor: '7C2D12',
+      sansHeadings: false,
+      sectionRule: true,
+      ruleColor: '94A3B8',
+    },
+    docx: {
+      headingColor: '1F3A5F',
+      linkColor: '7C2D12',
+      headingFont: 'Cambria',
+      bodyFont: 'Cambria',
+    },
+  },
+  sepia: {
+    label: 'Sepia',
+    description: 'Warm manuscript tones — browns and parchment accents',
+    pdf: {
+      headingColor: '7C4A21',
+      linkColor: 'A16207',
+      sansHeadings: false,
+      sectionRule: true,
+      ruleColor: 'D6BFA6',
+    },
+    docx: {
+      headingColor: '7C4A21',
+      linkColor: 'A16207',
+      headingFont: 'Georgia',
+      bodyFont: 'Georgia',
+    },
+  },
+  minimal: {
+    label: 'Minimal',
+    description: 'Near-black, no rules, understated gray links',
+    pdf: {
+      headingColor: '111827',
+      linkColor: '4B5563',
+      sansHeadings: false,
+      sectionRule: false,
+    },
+    docx: {
+      headingColor: '111827',
+      linkColor: '4B5563',
+      headingFont: 'Aptos',
+      bodyFont: 'Aptos',
+    },
+  },
+  elegant: {
+    label: 'Elegant',
+    description: 'Plum headings with hairline rules, slate links',
+    pdf: {
+      headingColor: '6D28D9',
+      linkColor: '334155',
+      sansHeadings: false,
+      sectionRule: true,
+      ruleColor: 'DDD6FE',
+    },
+    docx: {
+      headingColor: '6D28D9',
+      linkColor: '334155',
+      headingFont: 'Palatino Linotype',
+      bodyFont: 'Palatino Linotype',
+    },
+  },
+};
+
+/** Resolve a theme id safely (unknown → default). */
+function getTheme(id) {
+  return THEMES[id] || THEMES.default;
+}
+
+/** Menu/UI listing: [{id, label, description}] in definition order. */
+function listThemes() {
+  return Object.entries(THEMES).map(([id, t]) => ({
+    id,
+    label: t.label,
+    description: t.description,
+  }));
+}
+
+/**
+ * Build the LaTeX header implementing a theme's PDF look, or null for the
+ * default theme. Colors are inlined as hex literals — no user input reaches
+ * this string, so no LaTeX injection surface exists.
+ *
+ * @param {string} themeId
+ * @returns {string|null} full .tex header content
+ */
+function buildLatexThemeHeader(themeId) {
+  const theme = getTheme(themeId);
+  if (!theme.pdf) return null;
+
+  const p = theme.pdf;
+  const lines = ['% Export theme: ' + theme.label, '\\usepackage{xcolor}'];
+
+  if (p.sansHeadings) {
+    // helvet is in every TeX distribution's core; scale it to match body size
+    lines.push('\\usepackage[scaled=0.92]{helvet}');
+  }
+
+  lines.push(`\\definecolor{mcthemeheading}{HTML}{${p.headingColor}}`);
+  lines.push(`\\definecolor{mcthemelink}{HTML}{${p.linkColor}}`);
+  if (p.ruleColor) lines.push(`\\definecolor{mcthemerule}{HTML}{${p.ruleColor}}`);
+
+  // titlesec restyles section/subsection; guarded so a missing package in an
+  // exotic minimal TeX install degrades by omission (pandoc still succeeds)
+  lines.push('\\usepackage{titlesec}');
+  if (p.sansHeadings) lines.push('\\renewcommand{\\familydefault}{\\sfdefault}');
+  const rule = p.sectionRule && p.ruleColor
+    ? '{\\color{mcthemerule}\\titlerule[0.6pt]}'
+    : '';
+  lines.push(
+    `\\titleformat{\\section}{\\LARGE\\bfseries\\color{mcthemeheading}}{\\thesection}{0.8em}{}${rule}`
+  );
+  lines.push(
+    `\\titleformat{\\subsection}{\\Large\\bfseries\\color{mcthemeheading}}{\\thesubsection}{0.8em}{}`
+  );
+  lines.push(
+    `\\titleformat{\\subsubsection}{\\large\\bfseries\\color{mcthemeheading}}{\\thesubsubsection}{0.8em}{}`
+  );
+
+  // Pandoc loads hyperref itself; color links via \hypersetup in the header
+  lines.push('\\usepackage{etoolbox}');
+  lines.push('\\AfterEndPreamble{\\hypersetup{colorlinks=true,linkcolor=mcthemelink,urlcolor=mcthemelink}}');
+
+  return lines.join('\n') + '\n';
+}
+
+/**
+ * Apply a theme's DOCX styling by patching word/styles.xml in place.
+ * Patches Heading1-6, Title, Subtitle (color + font) and Hyperlink (color);
+ * Normal (body font) is only touched when the theme defines bodyFont.
+ *
+ * @param {string} docxPath .docx to patch (modified in place)
+ * @param {string} themeId
+ * @param {object} [io] injectable { PizZip, fs } for tests
+ */
+function applyDocxTheme(docxPath, themeId, io = {}) {
+  const PizZip = io.PizZip || require('pizzip');
+  const fs = io.fs || require('fs');
+  const theme = getTheme(themeId);
+  if (!theme.docx) return false;
+
+  const d = theme.docx;
+  const zip = new PizZip(fs.readFileSync(docxPath));
+  const stylesFile = zip.file('word/styles.xml');
+  if (!stylesFile) return false;
+  let xml = stylesFile.asText();
+
+  const headingIds = ['Title', 'Subtitle', 'Heading1', 'Heading2', 'Heading3', 'Heading4', 'Heading5', 'Heading6'];
+  for (const styleId of headingIds) {
+    // Match this style's <w:style …w:styleId="X">…</w:style> block (they
+    // never nest), then rewrite its rPr color/rFonts
+    const re = new RegExp(`(<w:style [^>]*w:styleId="${styleId}"[^>]*>)([\\s\\S]*?)(</w:style>)`);
+    const match = re.exec(xml);
+    if (!match) continue;
+    let inner = match[2];
+
+    // Drop any existing color/rFonts in the style's rPr, then insert ours
+    inner = inner.replace(/<w:color w:val="[0-9A-Fa-f]{6}"\s*\/>/g, '');
+    inner = inner.replace(/<w:rFonts[^>]*\/>/g, '');
+
+    const patch =
+      `<w:color w:val="${d.headingColor}"/>` +
+      (d.headingFont
+        ? `<w:rFonts w:ascii="${d.headingFont}" w:hAnsi="${d.headingFont}" w:cs="${d.headingFont}"/>`
+        : '');
+
+    if (inner.includes('<w:rPr>')) {
+      inner = inner.replace('<w:rPr>', `<w:rPr>${patch}`);
+    } else {
+      // Style without rPr: add one right after the <w:name …/> element
+      inner = inner.replace(/(<w:name [^>]*\/>)/, `$1<w:rPr>${patch}</w:rPr>`);
+    }
+    xml = xml.replace(match[0], `${match[1]}${inner}${match[3]}`);
+  }
+
+  // Hyperlink character style: recolor only
+  const hl = /(<w:style [^>]*w:styleId="Hyperlink"[^>]*>)([\s\S]*?)(<\/w:style>)/.exec(xml);
+  if (hl) {
+    let inner = hl[2].replace(/<w:color w:val="[0-9A-Fa-f]{6}"\s*\/>/g, '');
+    const patch = `<w:color w:val="${d.linkColor}"/>`;
+    if (inner.includes('<w:rPr>')) inner = inner.replace('<w:rPr>', `<w:rPr>${patch}`);
+    else inner = inner.replace(/(<w:name [^>]*\/>)/, `$1<w:rPr>${patch}</w:rPr>`);
+    xml = xml.replace(hl[0], `${hl[1]}${inner}${hl[3]}`);
+  }
+
+  // Body font: patch the docDefaults rPrDefault (affects Normal everywhere)
+  if (d.bodyFont) {
+    const patch = `<w:rFonts w:ascii="${d.bodyFont}" w:hAnsi="${d.bodyFont}" w:cs="${d.bodyFont}"/>`;
+    xml = xml.replace(
+      /(<w:docDefaults>\s*<w:rPrDefault>\s*<w:rPr>)/,
+      `$1${patch}`
+    );
+  }
+
+  zip.file('word/styles.xml', xml);
+  fs.writeFileSync(docxPath, zip.generate({ type: 'nodebuffer' }));
+  return true;
+}
+
+module.exports = { THEMES, getTheme, listThemes, buildLatexThemeHeader, applyDocxTheme };
diff --git a/src/renderer.js b/src/renderer.js
index 5d5ae39..f71f293 100644
--- a/src/renderer.js
+++ b/src/renderer.js
@@ -2964,6 +2964,26 @@ function initializeExportForm(format) {
     document.getElementById('custom-geometry').style.display = 'none';
   }
 
+  // Export theme picker: shown for the formats that support theming; options
+  // come straight from the shared theme definitions (labels + descriptions)
+  const themeRow = document.getElementById('export-theme-row');
+  const themeSelect = document.getElementById('export-theme');
+  if (themeRow && themeSelect) {
+    const themeable = format === 'pdf' || format === 'docx';
+    themeRow.style.display = themeable ? 'flex' : 'none';
+    if (themeSelect.options.length === 0) {
+      const { listThemes } = require('./main/ExportThemes');
+      for (const theme of listThemes()) {
+        const option = document.createElement('option');
+        option.value = theme.id;
+        option.textContent = theme.label;
+        option.title = theme.description;
+        themeSelect.appendChild(option);
+      }
+    }
+    themeSelect.value = 'default';
+  }
+
   // Toggle and reset Reveal.js-specific fields
   const revealjsOnly = document.querySelector('.revealjs-only');
   if (revealjsOnly) {
@@ -3076,6 +3096,12 @@ function collectExportOptions() {
     }
   }
 
+  // Export theme is available in basic mode too (PDF + DOCX)
+  const themeSelect = document.getElementById('export-theme');
+  if (themeSelect && (currentExportFormat === 'pdf' || currentExportFormat === 'docx')) {
+    options.theme = themeSelect.value || 'default';
+  }
+
   // Collect page size and orientation (always collected, from basic options)
   const pageSize = document.getElementById('page-size').value;
   const pageOrientation = document.getElementById('page-orientation').value;
diff --git a/src/renderer/export-presets.js b/src/renderer/export-presets.js
index b73de0c..676b7ac 100644
--- a/src/renderer/export-presets.js
+++ b/src/renderer/export-presets.js
@@ -120,6 +120,12 @@ function captureDialogOptions() {
         : geometrySelect;
   }
 
+  // Export theme (PDF + DOCX) — stored with presets like engine/geometry
+  if (format === 'pdf' || format === 'docx') {
+    const theme = valueOf('export-theme');
+    if (theme) options.theme = theme;
+  }
+
   if (format === 'revealjs') {
     options.revealTheme = valueOf('reveal-theme');
     options.revealTransition = valueOf('reveal-transition');
@@ -206,6 +212,15 @@ function applyPresetToDialog(preset) {
     setVisible('custom-geometry', true);
   }
 
+  // Export theme (guard: a preset saved with a newer/older theme list still
+  // applies, falling back to default for unknown ids)
+  const themeSelect = elementById('export-theme');
+  if (themeSelect) {
+    const theme = advancedOptions.theme || 'default';
+    const hasTheme = Array.from(themeSelect.options).some((opt) => opt.value === theme);
+    setValue('export-theme', hasTheme ? theme : 'default');
+  }
+
   // Reveal.js options
   setValue('reveal-theme', advancedOptions.revealTheme || 'black');
   setValue('reveal-transition', advancedOptions.revealTransition || 'slide');
diff --git a/tests/main/ExportThemes.test.js b/tests/main/ExportThemes.test.js
new file mode 100644
index 0000000..171369b
--- /dev/null
+++ b/tests/main/ExportThemes.test.js
@@ -0,0 +1,181 @@
+/**
+ * @jest-environment node
+ *
+ * ExportThemes tests: LaTeX header generation (content + injection safety)
+ * and DOCX styles.xml patching against a minimal pandoc-style fixture.
+ */
+const fs = require('fs');
+const os = require('os');
+const path = require('path');
+const PizZip = require('pizzip');
+const {
+  THEMES,
+  getTheme,
+  listThemes,
+  buildLatexThemeHeader,
+  applyDocxTheme,
+} = require('../../src/main/ExportThemes');
+
+// Minimal pandoc-like word/styles.xml: heading + hyperlink styles + docDefaults
+const STYLES_XML = `<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<w:styles xmlns:w="http://schemas.openxmlformats.org/wordprocessingml/2006/main">
+  <w:docDefaults>
+    <w:rPrDefault><w:rPr><w:sz w:val="22"/></w:rPr></w:rPrDefault>
+  </w:docDefaults>
+  <w:style w:type="paragraph" w:styleId="Heading1">
+    <w:name w:val="heading 1"/>
+    <w:pPr><w:outlineLvl w:val="0"/></w:pPr>
+    <w:rPr><w:b/><w:sz w:val="32"/></w:rPr>
+  </w:style>
+  <w:style w:type="paragraph" w:styleId="Heading2">
+    <w:name w:val="heading 2"/>
+    <w:rPr><w:b/><w:color w:val="2E74B5"/></w:rPr>
+  </w:style>
+  <w:style w:type="paragraph" w:styleId="Title">
+    <w:name w:val="Title"/>
+    <w:rPr><w:b/></w:rPr>
+  </w:style>
+  <w:style w:type="character" w:styleId="Hyperlink">
+    <w:name w:val="Hyperlink"/>
+    <w:rPr><w:color w:val="0563C1"/><w:u w:val="single"/></w:rPr>
+  </w:style>
+</w:styles>`;
+
+function writeDocxFixture(filePath) {
+  const zip = new PizZip();
+  zip.file(
+    '[Content_Types].xml',
+    '<?xml version="1.0"?><Types xmlns="http://schemas.openxmlformats.org/package/2006/content-types"/>'
+  );
+  zip.file('word/styles.xml', STYLES_XML);
+  zip.file('word/document.xml', '<w:document/>');
+  fs.writeFileSync(filePath, zip.generate({ type: 'nodebuffer' }));
+}
+
+function readStyles(filePath) {
+  return new PizZip(fs.readFileSync(filePath)).file('word/styles.xml').asText();
+}
+
+describe('ExportThemes', () => {
+  describe('definitions', () => {
+    it('lists themes with labels in a stable order, default first', () => {
+      const list = listThemes();
+      expect(list[0].id).toBe('default');
+      expect(list.map((t) => t.id)).toEqual(Object.keys(THEMES));
+      expect(list.every((t) => t.label && t.description)).toBe(true);
+    });
+
+    it('falls back to default for unknown ids', () => {
+      expect(getTheme('nope').id).toBeUndefined(); // default theme has no id field
+      expect(getTheme('nope').label).toBe('Default (Pandoc)');
+      expect(getTheme('modern').label).toBe('Modern');
+    });
+  });
+
+  describe('buildLatexThemeHeader', () => {
+    it('returns null for the default theme', () => {
+      expect(buildLatexThemeHeader('default')).toBeNull();
+      expect(buildLatexThemeHeader('unknown-id')).toBeNull();
+    });
+
+    it('emits xcolor, heading color, and titlesec formatting', () => {
+      const tex = buildLatexThemeHeader('modern');
+      expect(tex).toContain('\\usepackage{xcolor}');
+      // \definecolor{mcthemeheading}{HTML}{1E4FD8}
+      expect(tex).toContain('\\definecolor{mcthemeheading}{HTML}{1E4FD8}');
+      expect(tex).toContain('\\definecolor{mcthemelink}{HTML}{0E7490}');
+      expect(tex).toContain('\\titleformat{\\section}');
+      // modern = sans headings
+      expect(tex).toContain('helvet');
+    });
+
+    it('omits section rules and helvet for themes that decline them', () => {
+      const tex = buildLatexThemeHeader('minimal');
+      expect(tex).not.toContain('helvet');
+      expect(tex).not.toContain('titlerule');
+    });
+
+    it('only inlines hex literals (no user input reaches LaTeX)', () => {
+      for (const id of Object.keys(THEMES)) {
+        const tex = buildLatexThemeHeader(id);
+        if (!tex) continue;
+        // Every color is the {HTML}{HEXHEXHEX} literal form
+        const colors = tex.match(/\{HTML\}\{([^}]*)\}/g) || [];
+        expect(colors.length).toBeGreaterThan(0);
+        for (const c of colors) {
+          expect(c).toMatch(/^\{HTML\}\{[A-F0-9]{6}\}$/);
+        }
+      }
+    });
+  });
+
+  describe('applyDocxTheme', () => {
+    let tmpDir, docxPath;
+
+    beforeEach(() => {
+      tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'theme_'));
+      docxPath = path.join(tmpDir, 'doc.docx');
+      writeDocxFixture(docxPath);
+    });
+
+    afterEach(() => {
+      fs.rmSync(tmpDir, { recursive: true, force: true, maxRetries: 5, retryDelay: 100 });
+    });
+
+    it('is a no-op returning false for the default theme', () => {
+      expect(applyDocxTheme(docxPath, 'default')).toBe(false);
+      expect(readStyles(docxPath)).toBe(STYLES_XML);
+    });
+
+    it('recolors headings, swaps heading font, and recolors hyperlinks', () => {
+      const applied = applyDocxTheme(docxPath, 'modern');
+      expect(applied).toBe(true);
+
+      const xml = readStyles(docxPath);
+      // Heading color + font injected
+      expect(xml).toContain('<w:color w:val="1E4FD8"/>');
+      expect(xml).toContain('w:ascii="Calibri"');
+      // Heading2's old color is replaced, not duplicated
+      expect(xml).not.toContain('2E74B5');
+      const h1 = /w:styleId="Heading1"[\s\S]*?<\/w:style>/.exec(xml)[0];
+      expect(h1.match(/<w:color/g)).toHaveLength(1);
+      // Hyperlink recolored
+      expect(xml).not.toContain('0563C1');
+      expect(xml).toContain('<w:color w:val="0E7490"/>');
+      // Body font lands in docDefaults
+      expect(xml).toMatch(/<w:rPrDefault>\s*<w:rPr><w:rFonts w:ascii="Calibri"/);
+    });
+
+    it('preserves unrelated style content', () => {
+      applyDocxTheme(docxPath, 'classic');
+      const xml = readStyles(docxPath);
+      expect(xml).toContain('<w:sz w:val="32"/>');
+      expect(xml).toContain('<w:u w:val="single"/>');
+      expect(xml).toContain('<w:outlineLvl w:val="0"/>');
+    });
+
+    it('tolerates styles.xml without an rPr block in a style', () => {
+      // Title style in the fixture has rPr; craft one without it
+      const bare = STYLES_XML.replace(
+        /(<w:style w:type="paragraph" w:styleId="Title">\s*<w:name w:val="Title"\/>)\s*<w:rPr><w:b\/><\/w:rPr>/,
+        '$1'
+      );
+      const zip = new PizZip();
+      zip.file('[Content_Types].xml', '<Types/>');
+      zip.file('word/styles.xml', bare);
+      fs.writeFileSync(docxPath, zip.generate({ type: 'nodebuffer' }));
+
+      expect(applyDocxTheme(docxPath, 'sepia')).toBe(true);
+      const xml = readStyles(docxPath);
+      const title = /w:styleId="Title"[\s\S]*?<\/w:style>/.exec(xml)[0];
+      expect(title).toContain('<w:color w:val="7C4A21"/>');
+    });
+
+    it('returns false when styles.xml is missing', () => {
+      const zip = new PizZip();
+      zip.file('[Content_Types].xml', '<Types/>');
+      fs.writeFileSync(docxPath, zip.generate({ type: 'nodebuffer' }));
+      expect(applyDocxTheme(docxPath, 'modern')).toBe(false);
+    });
+  });
+});
diff --git a/tests/main/ImageOperations.test.js b/tests/main/ImageOperations.test.js
index 635b758..b286dbe 100644
--- a/tests/main/ImageOperations.test.js
+++ b/tests/main/ImageOperations.test.js
@@ -15,7 +15,15 @@ describe('ImageOperations', () => {
       .png()
       .toFile(inputPath);
   });
-  afterEach(() => fs.rmSync(tmpDir, { recursive: true, force: true }));
+  // Windows: sharp can hold the file handle briefly after await returns,
+// so plain rmSync throws EPERM — retry and tolerate stale temp dirs.
+afterEach(() => {
+  try {
+    fs.rmSync(tmpDir, { recursive: true, force: true, maxRetries: 5, retryDelay: 100 });
+  } catch {
+    /* leftover temp dir is cosmetic on locked-file platforms */
+  }
+});
 
   test('imageConvert converts PNG to JPEG', async () => {
     const outputPath = path.join(tmpDir, 'out.jpg');
diff --git a/tests/main/PDFBatchOperations.test.js b/tests/main/PDFBatchOperations.test.js
index 8eba832..3cff996 100644
--- a/tests/main/PDFBatchOperations.test.js
+++ b/tests/main/PDFBatchOperations.test.js
@@ -1,5 +1,6 @@
 /**
  * @jest-environment node
+ * @jest-environment-options {"testTimeout": 30000}
  *
  * PDFBatchOperations.js tests for Task 22's batch PDF operations: the folder
  * loop that applies one PDFOperations.executeOperation() op to every .pdf in an
diff --git a/tests/main/PDFOperations.test.js b/tests/main/PDFOperations.test.js
index 540c889..ca9f458 100644
--- a/tests/main/PDFOperations.test.js
+++ b/tests/main/PDFOperations.test.js
@@ -1,5 +1,6 @@
 /**
  * @jest-environment node
+ * @jest-environment-options {"testTimeout": 30000}
  *
  * PDFOperations.js tests for Task 15's new operations: extractText, pageNumbers,
  * crop, extractImages. Uses pdf-lib to build minimal fixture PDFs at test time,
@@ -47,13 +48,19 @@ describe('PDFOperations - Task 15 new operations', () => {
   });
 
   describe('pdfExtractText', () => {
-    it('extracts text from all pages', async () => {
-      const result = await PDFOperations.pdfExtractText({ inputPath });
+    it(
+      'extracts text from all pages',
+      async () => {
+        const result = await PDFOperations.pdfExtractText({ inputPath });
 
-      expect(result.success).toBe(true);
-      expect(result.text).toContain('Hello Task 15 Page One');
-      expect(result.text).toContain('Second Page Content');
-    });
+        expect(result.success).toBe(true);
+        expect(result.text).toContain('Hello Task 15 Page One');
+        expect(result.text).toContain('Second Page Content');
+      },
+      // First pdfjs-dist legacy import can exceed the 5s default on slower
+      // CI runners (observed on windows-latest)
+      30000
+    );
 
     it('returns failure for a nonexistent file', async () => {
       const result = await PDFOperations.pdfExtractText({
@@ -150,38 +157,42 @@ describe('PDFOperations - Task 15 new operations', () => {
   });
 
   describe('pdfExtractImages', () => {
-    it('extracts embedded raster images as PNG files', async () => {
-      const imgPath = path.join(tmpDir, 'red.png');
-      await sharp({
-        create: { width: 20, height: 20, channels: 3, background: { r: 255, g: 0, b: 0 } },
-      })
-        .png()
-        .toFile(imgPath);
+    it(
+      'extracts embedded raster images as PNG files',
+      async () => {
+        const imgPath = path.join(tmpDir, 'red.png');
+        await sharp({
+          create: { width: 20, height: 20, channels: 3, background: { r: 255, g: 0, b: 0 } },
+        })
+          .png()
+          .toFile(imgPath);
 
-      const doc = await PDFDocument.create();
-      const page = doc.addPage([300, 300]);
-      const pngImage = await doc.embedPng(fs.readFileSync(imgPath));
-      page.drawImage(pngImage, { x: 50, y: 50, width: 100, height: 100 });
+        const doc = await PDFDocument.create();
+        const page = doc.addPage([300, 300]);
+        const pngImage = await doc.embedPng(fs.readFileSync(imgPath));
+        page.drawImage(pngImage, { x: 50, y: 50, width: 100, height: 100 });
 
-      const imagePdfPath = path.join(tmpDir, 'with-image.pdf');
-      fs.writeFileSync(imagePdfPath, await doc.save());
+        const imagePdfPath = path.join(tmpDir, 'with-image.pdf');
+        fs.writeFileSync(imagePdfPath, await doc.save());
 
-      const outputDir = path.join(tmpDir, 'extracted');
-      const result = await PDFOperations.pdfExtractImages({
-        inputPath: imagePdfPath,
-        outputDir,
-      });
+        const outputDir = path.join(tmpDir, 'extracted');
+        const result = await PDFOperations.pdfExtractImages({
+          inputPath: imagePdfPath,
+          outputDir,
+        });
 
-      expect(result.success).toBe(true);
-      expect(result.count).toBeGreaterThanOrEqual(1);
-      expect(result.files.length).toBe(result.count);
+        expect(result.success).toBe(true);
+        expect(result.count).toBeGreaterThanOrEqual(1);
+        expect(result.files.length).toBe(result.count);
 
-      for (const file of result.files) {
-        expect(fs.existsSync(file)).toBe(true);
-        const meta = await sharp(file).metadata();
-        expect(meta.format).toBe('png');
-      }
-    });
+        for (const file of result.files) {
+          expect(fs.existsSync(file)).toBe(true);
+          const meta = await sharp(file).metadata();
+          expect(meta.format).toBe('png');
+        }
+      },
+      30000 // pdfjs import + sharp decode on slower CI runners
+    );
 
     it('returns zero images for a text-only PDF', async () => {
       const outputDir = path.join(tmpDir, 'extracted-none');
diff --git a/tests/monospace-font-config.test.js b/tests/monospace-font-config.test.js
index 398d682..c7a3614 100644
--- a/tests/monospace-font-config.test.js
+++ b/tests/monospace-font-config.test.js
@@ -22,7 +22,10 @@ describe('MonospaceFontConfig', () => {
       (p) => !p.includes('app.asar.unpacked') && p.endsWith('JetBrainsMono-Regular.ttf')
     );
     const p = MonospaceFontConfig.getMonoFontTtfPath('jetbrains-mono', 400);
-    expect(p).toMatch(/assets\/fonts\/JetBrainsMono-Regular\.ttf$/);
+    // Normalize separators: Windows paths are backslash-joined
+    expect(p.split(require('path').sep).join('/')).toMatch(
+      /assets\/fonts\/JetBrainsMono-Regular\.ttf$/
+    );
   });
 
   test('returns packaged asar.unpacked path when present and file exists', () => {