From c0a97923fe0a42671d7fa054c1119fdd5f8148e7 Mon Sep 17 00:00:00 2001
From: Trevor Austin <trevor@tavernresearch.com>
Date: Wed, 1 Apr 2026 14:00:21 -0500
Subject: [PATCH 01/16] add design spec for static site generation migration

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 ...026-04-01-static-site-generation-design.md | 129 ++++++++++++++++++
 1 file changed, 129 insertions(+)
 create mode 100644 docs/specs/2026-04-01-static-site-generation-design.md

diff --git a/docs/specs/2026-04-01-static-site-generation-design.md b/docs/specs/2026-04-01-static-site-generation-design.md
new file mode 100644
index 0000000..b8432d0
--- /dev/null
+++ b/docs/specs/2026-04-01-static-site-generation-design.md
@@ -0,0 +1,129 @@
+# Static Site Generation Migration
+
+## Overview
+
+Migrate the course materials site from client-side remarkjs rendering to a Python-based static site generator that produces one HTML page per slide. The generator uses Jinja2 for templates and python-markdown for Markdown rendering. Output is static HTML suitable for GitHub Pages or any static host.
+
+## Markdown Processing Pipeline
+
+The build script reads each `lecture_notes/week_N.md` (excluding `week_8_old.md`) and processes it through:
+
+1. **Split on `---`** — split the file into individual slide strings. The `---` must appear on its own line to count as a slide boundary.
+
+2. **Strip remark syntax** from each slide — a preprocessor that:
+   - Removes `class: ...` directives at the top of slides. These classes (e.g., `center`, `middle`, `agenda`, `split`) are applied as CSS classes on the slide's container `<div>` in the output HTML, so their visual effect can be preserved via the stylesheet.
+   - Converts `.classname[content]` wrappers to `<span class="classname">content</span>` (or `<div>` for block-level content). This preserves classes like `.big`, `.half`, `.credit`, `.gallery` so they can be styled via CSS.
+   - Removes `???` presenter note blocks — everything from a line containing only `???` (outside of fenced code blocks) to the end of the slide.
+   - Removes `--` incremental reveal markers — only when `--` appears as the sole content on a line, outside of fenced code blocks.
+
+3. **Render Markdown to HTML** — each slide's markdown is run through python-markdown with extensions for fenced code blocks, syntax highlighting (codehilite/Pygments), and tables.
+
+4. **Render into Jinja2 template** — the slide HTML is injected into a `slide.html` template with navigation data, prev/next links, and site CSS.
+
+## Images and Asset Paths
+
+- `lecture_notes/images/` is copied to `_site/lecture_notes/images/`.
+- Image references in slide markdown use relative paths like `images/foo.png`. Since slides output to `_site/lecture_notes/week_N/1/index.html`, these relative paths will not resolve correctly. The build script rewrites image `src` attributes in generated slide HTML to use absolute paths (e.g., `/lecture_notes/images/foo.png`).
+- Absolute links in the markdown (e.g., `/examples/week_2/columns.html`) are left as-is — they resolve correctly from the site root.
+- External image URLs (e.g., xkcd, imgflip) are left as-is.
+
+## Output Structure
+
+```
+_site/
+├── index.html                     # Course homepage
+├── syllabus/
+│   └── index.html                 # Rendered syllabus
+├── lecture_notes/
+│   ├── index.html                 # Week listing page
+│   ├── images/                    # Copied from lecture_notes/images/
+│   └── week_1/
+│       ├── 1/index.html           # Slide 1
+│       ├── 2/index.html           # Slide 2
+│       └── ...
+│   └── week_2/
+│       └── ...
+├── examples/                      # Copied as-is (including examples/images/)
+│   ├── week_1/
+│   └── ...
+├── css/
+│   └── style.css                  # Site stylesheet
+└── js/
+    └── navigation.js              # Keyboard nav
+```
+
+- Clean URLs via `index.html` inside directories (e.g., `/lecture_notes/week_1/3/`)
+- Examples directory copied verbatim, including `examples/images/`
+- CSS and JS are shared across all pages
+- `trevor.html` and `yourname.html` from the repo root are not included in the output (student exercise artifacts)
+
+## Navigation
+
+A vanilla JS file (`navigation.js`) handles keyboard navigation:
+
+- **Left/Up arrow** — previous slide
+- **Right/Down arrow** — next slide
+- **Home** — first slide of the current week
+
+Each slide's HTML includes data attributes with prev/next URLs and slide count. The JS reads these and navigates via `window.location`.
+
+Each slide page also has a visible nav bar:
+- Week title and slide number (e.g., "Week 3 — 12 / 34")
+- Clickable prev/next arrows
+- Link back to course homepage
+
+## Templates
+
+Four Jinja2 templates:
+
+1. **`base.html`** — shared shell: `<head>`, CSS link, nav bar, JS link, `{% block content %}`
+2. **`slide.html`** — extends base. Renders a single slide's HTML content with navigation data (prev/next URLs, slide number, total count, week number).
+3. **`page.html`** — extends base. For non-slide pages (syllabus). No slide navigation, just content.
+4. **`lecture_index.html`** — extends base. Lists all weeks with links to their first slide. Generated at `/lecture_notes/index.html`.
+
+The homepage is a Jinja2 template rendered directly (`templates/index.html`), not generated from markdown, since it has custom layout.
+
+## Stylesheet
+
+The new `css/style.css` is written from scratch but ports relevant visual rules from the existing `lecture_notes/styles/style.css`:
+- Slide container classes preserved from `class:` directives (`center`, `middle`, `split`, `agenda`, `gallery`, etc.)
+- Inline content classes preserved from `.classname[]` syntax (`big`, `half`, `credit`, `animate`, etc.)
+- Typography (existing Google Fonts: Yanone Kaffeesatz, Droid Serif, Ubuntu Mono)
+- Code block styling (Pygments theme)
+
+## Build Script
+
+**`build.py`** — single entry point. `python build.py`:
+
+1. Cleans and recreates `_site/`
+2. Walks `lecture_notes/week_*.md` (skipping `*_old.md`), runs each through the split/preprocess/render pipeline
+3. Generates the lecture notes index page
+4. Renders the homepage and syllabus (from `syllabus.md` at the repo root, using the `page.html` template)
+5. Copies `examples/`, `lecture_notes/images/`, and static assets (CSS, JS) into `_site/`
+
+**Local preview:** `python -m http.server -d _site`
+
+## Dependencies
+
+In `requirements.txt`:
+- `Jinja2` — templating
+- `Markdown` — python-markdown for rendering
+- `Pygments` — syntax highlighting for code blocks
+
+## Deployment
+
+- Output is a static `_site/` directory deployable anywhere
+- Primary target: GitHub Pages via GitHub Actions (build on push, deploy to Pages)
+- Alternative: rsync or any static file host
+- The existing `deploy.sh` (rsync to uchicagowebdev.com) is superseded but can be kept for backwards compatibility during transition
+
+## Cleanup
+
+After migration is complete, the following files become unused and can be removed:
+- `lecture_notes/scripts/` (remark-v0.15.0.min.js, require.js, slides.js)
+- `lecture_notes/styles/` (replaced by `css/style.css`)
+- `lecture_notes/index.html` (replaced by generated output)
+
+## Markdown File Organization
+
+Markdown files stay as one file per week (`week_N.md`). The build system splits on `---` to produce individual slide pages. This keeps authoring simple and the files human-readable.

From cc206b3cd7e52fe441bd9c529209b965968e7512 Mon Sep 17 00:00:00 2001
From: Trevor Austin <trevor@tavernresearch.com>
Date: Wed, 1 Apr 2026 14:13:35 -0500
Subject: [PATCH 02/16] add implementation plan for static site generation

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 .../2026-04-01-static-site-generation.md      | 1339 +++++++++++++++++
 1 file changed, 1339 insertions(+)
 create mode 100644 docs/plans/2026-04-01-static-site-generation.md

diff --git a/docs/plans/2026-04-01-static-site-generation.md b/docs/plans/2026-04-01-static-site-generation.md
new file mode 100644
index 0000000..1924999
--- /dev/null
+++ b/docs/plans/2026-04-01-static-site-generation.md
@@ -0,0 +1,1339 @@
+# Static Site Generation Implementation Plan
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Build a Python static site generator that converts remarkjs-flavored markdown into individual HTML slide pages with keyboard navigation.
+
+**Architecture:** A single `build.py` script that splits weekly markdown files into slides, strips remark syntax, renders markdown to HTML via python-markdown, and injects the result into Jinja2 templates. Output is a `_site/` directory of static HTML.
+
+**Tech Stack:** Python 3, Jinja2, python-markdown, Pygments
+
+**Spec:** `docs/specs/2026-04-01-static-site-generation-design.md`
+
+---
+
+## File Structure
+
+```
+build.py                          # Main build script
+requirements.txt                  # Python dependencies
+preprocessor.py                   # Remark syntax stripping and slide splitting
+templates/
+  base.html                       # Shared HTML shell
+  slide.html                      # Single slide page
+  page.html                       # Generic content page (syllabus)
+  index.html                      # Course homepage
+  lecture_index.html              # Week listing page
+static/
+  css/style.css                   # Site stylesheet (ported from remark CSS)
+  js/navigation.js                # Keyboard slide navigation
+tests/
+  test_preprocessor.py            # Tests for remark syntax stripping
+  test_build.py                   # Integration tests for build output
+```
+
+---
+
+### Task 1: Project Scaffolding
+
+**Files:**
+- Create: `requirements.txt`
+- Create: `tests/__init__.py`
+- Create: `tests/test_preprocessor.py` (empty initially)
+
+- [ ] **Step 1: Create `requirements.txt`**
+
+```
+Jinja2>=3.1
+Markdown>=3.5
+Pygments>=2.17
+```
+
+- [ ] **Step 2: Create empty test package**
+
+```bash
+mkdir -p tests
+touch tests/__init__.py
+```
+
+- [ ] **Step 3: Install dependencies**
+
+Run: `pip install -r requirements.txt`
+Expected: Successfully installs Jinja2, Markdown, Pygments and their dependencies.
+
+- [ ] **Step 4: Commit**
+
+```bash
+git add requirements.txt tests/__init__.py
+git commit -m "add project scaffolding for static site generator"
+```
+
+---
+
+### Task 2: Slide Splitting
+
+**Files:**
+- Create: `preprocessor.py`
+- Create: `tests/test_preprocessor.py`
+
+- [ ] **Step 1: Write failing test for basic slide splitting**
+
+`tests/test_preprocessor.py`:
+```python
+from preprocessor import split_slides
+
+
+def test_split_slides_basic():
+    md = "# Slide 1\nContent\n---\n# Slide 2\nMore content"
+    slides = split_slides(md)
+    assert len(slides) == 2
+    assert "# Slide 1" in slides[0]
+    assert "# Slide 2" in slides[1]
+
+
+def test_split_slides_ignores_hr_in_code_block():
+    md = "# Slide 1\n```\n---\n```\n---\n# Slide 2"
+    slides = split_slides(md)
+    assert len(slides) == 2
+    assert "---" in slides[0]  # The --- inside the code block stays
+
+
+def test_split_slides_trims_whitespace():
+    md = "# Slide 1\n\n---\n\n# Slide 2\n"
+    slides = split_slides(md)
+    assert slides[0].strip() == "# Slide 1"
+    assert slides[1].strip() == "# Slide 2"
+```
+
+- [ ] **Step 2: Run tests to verify they fail**
+
+Run: `python -m pytest tests/test_preprocessor.py -v`
+Expected: FAIL — `ImportError: cannot import name 'split_slides'`
+
+- [ ] **Step 3: Implement `split_slides`**
+
+`preprocessor.py`:
+```python
+import re
+
+
+def split_slides(markdown: str) -> list[str]:
+    """Split markdown on --- slide boundaries, ignoring --- inside fenced code blocks."""
+    slides = []
+    current_slide = []
+    in_code_block = False
+
+    for line in markdown.split("\n"):
+        stripped = line.strip()
+
+        # Track fenced code blocks
+        if stripped.startswith("```"):
+            in_code_block = not in_code_block
+
+        # A line containing only --- outside a code block is a slide boundary
+        if stripped == "---" and not in_code_block:
+            slides.append("\n".join(current_slide))
+            current_slide = []
+        else:
+            current_slide.append(line)
+
+    # Don't forget the last slide
+    if current_slide:
+        slides.append("\n".join(current_slide))
+
+    # Strip leading/trailing whitespace from each slide, drop empty slides
+    return [s.strip() for s in slides if s.strip()]
+```
+
+- [ ] **Step 4: Run tests to verify they pass**
+
+Run: `python -m pytest tests/test_preprocessor.py -v`
+Expected: All 3 tests PASS.
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add preprocessor.py tests/test_preprocessor.py
+git commit -m "add slide splitting with fenced code block awareness"
+```
+
+---
+
+### Task 3: Strip Class Directives
+
+**Files:**
+- Modify: `preprocessor.py`
+- Modify: `tests/test_preprocessor.py`
+
+- [ ] **Step 1: Write failing tests**
+
+Append to `tests/test_preprocessor.py`:
+```python
+from preprocessor import strip_class_directive
+
+
+def test_strip_class_directive_basic():
+    slide = "class: center, middle\n# Title"
+    content, classes = strip_class_directive(slide)
+    assert content.strip() == "# Title"
+    assert classes == ["center", "middle"]
+
+
+def test_strip_class_directive_none():
+    slide = "# No class here"
+    content, classes = strip_class_directive(slide)
+    assert content.strip() == "# No class here"
+    assert classes == []
+
+
+def test_strip_class_directive_single():
+    slide = "class: agenda\n# Agenda Items"
+    content, classes = strip_class_directive(slide)
+    assert content.strip() == "# Agenda Items"
+    assert classes == ["agenda"]
+```
+
+- [ ] **Step 2: Run tests to verify they fail**
+
+Run: `python -m pytest tests/test_preprocessor.py::test_strip_class_directive_basic -v`
+Expected: FAIL — `ImportError`
+
+- [ ] **Step 3: Implement `strip_class_directive`**
+
+Add to `preprocessor.py`:
+```python
+def strip_class_directive(slide: str) -> tuple[str, list[str]]:
+    """Remove 'class: ...' directive from top of slide. Returns (content, class_list)."""
+    lines = slide.split("\n")
+    if lines and lines[0].strip().startswith("class:"):
+        class_line = lines[0].strip()
+        class_str = class_line[len("class:"):].strip()
+        classes = [c.strip() for c in class_str.split(",")]
+        return "\n".join(lines[1:]), classes
+    return slide, []
+```
+
+- [ ] **Step 4: Run tests to verify they pass**
+
+Run: `python -m pytest tests/test_preprocessor.py -v -k "class_directive"`
+Expected: All 3 tests PASS.
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add preprocessor.py tests/test_preprocessor.py
+git commit -m "add class directive stripping from slides"
+```
+
+---
+
+### Task 4: Strip Presenter Notes and Incremental Reveals
+
+**Files:**
+- Modify: `preprocessor.py`
+- Modify: `tests/test_preprocessor.py`
+
+- [ ] **Step 1: Write failing tests**
+
+Append to `tests/test_preprocessor.py`:
+```python
+from preprocessor import strip_presenter_notes, strip_incremental_reveals
+
+
+def test_strip_presenter_notes_basic():
+    slide = "# Slide\nContent\n\n???\n\nThese are notes"
+    result = strip_presenter_notes(slide)
+    assert "Content" in result
+    assert "notes" not in result
+    assert "???" not in result
+
+
+def test_strip_presenter_notes_no_notes():
+    slide = "# Slide\nContent"
+    result = strip_presenter_notes(slide)
+    assert result == slide
+
+
+def test_strip_presenter_notes_ignores_code_block():
+    slide = "# Slide\n```\n???\n```\nMore content"
+    result = strip_presenter_notes(slide)
+    assert "???" in result
+    assert "More content" in result
+
+
+def test_strip_incremental_reveals():
+    slide = "# Slide\nFirst point\n\n--\n\nSecond point"
+    result = strip_incremental_reveals(slide)
+    assert "First point" in result
+    assert "Second point" in result
+    assert "\n--\n" not in result
+
+
+def test_strip_incremental_reveals_ignores_code_block():
+    slide = "```\n--\n```"
+    result = strip_incremental_reveals(slide)
+    assert "--" in result
+```
+
+- [ ] **Step 2: Run tests to verify they fail**
+
+Run: `python -m pytest tests/test_preprocessor.py -v -k "presenter or incremental"`
+Expected: FAIL — `ImportError`
+
+- [ ] **Step 3: Implement both functions**
+
+Add to `preprocessor.py`:
+```python
+def strip_presenter_notes(slide: str) -> str:
+    """Remove everything from a standalone ??? line to end of slide, outside code blocks."""
+    lines = slide.split("\n")
+    result = []
+    in_code_block = False
+
+    for line in lines:
+        stripped = line.strip()
+
+        if stripped.startswith("```"):
+            in_code_block = not in_code_block
+
+        if stripped == "???" and not in_code_block:
+            break  # Drop everything from here to end of slide
+
+        result.append(line)
+
+    return "\n".join(result).rstrip()
+
+
+def strip_incremental_reveals(slide: str) -> str:
+    """Remove standalone -- lines (incremental reveal markers) outside code blocks."""
+    lines = slide.split("\n")
+    result = []
+    in_code_block = False
+
+    for line in lines:
+        stripped = line.strip()
+
+        if stripped.startswith("```"):
+            in_code_block = not in_code_block
+
+        if stripped == "--" and not in_code_block:
+            continue  # Skip this line
+
+        result.append(line)
+
+    return "\n".join(result)
+```
+
+- [ ] **Step 4: Run tests to verify they pass**
+
+Run: `python -m pytest tests/test_preprocessor.py -v -k "presenter or incremental"`
+Expected: All 5 tests PASS.
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add preprocessor.py tests/test_preprocessor.py
+git commit -m "add presenter notes and incremental reveal stripping"
+```
+
+---
+
+### Task 5: Convert `.classname[content]` Wrappers
+
+**Files:**
+- Modify: `preprocessor.py`
+- Modify: `tests/test_preprocessor.py`
+
+- [ ] **Step 1: Write failing tests**
+
+Append to `tests/test_preprocessor.py`:
+```python
+from preprocessor import convert_class_wrappers
+
+
+def test_convert_class_wrappers_inline():
+    text = "Some .big[**bold text**] here"
+    result = convert_class_wrappers(text)
+    assert result == 'Some <span class="big">**bold text**</span> here'
+
+
+def test_convert_class_wrappers_line_start_with_trailing_text():
+    """A .classname[] at line start with trailing text is inline, not block."""
+    text = ".big[**0.1 second**] is about the limit for the user"
+    result = convert_class_wrappers(text)
+    assert result == '<span class="big">**0.1 second**</span> is about the limit for the user'
+
+
+def test_convert_class_wrappers_block_whole_line():
+    text = ".half[![Image](foo.png)]"
+    result = convert_class_wrappers(text)
+    assert result == '<div class="half" markdown="1">\n\n![Image](foo.png)\n\n</div>'
+
+
+def test_convert_class_wrappers_credit():
+    text = ".credit[https://xkcd.com/327/]"
+    result = convert_class_wrappers(text)
+    assert result == '<div class="credit" markdown="1">\n\nhttps://xkcd.com/327/\n\n</div>'
+
+
+def test_convert_class_wrappers_multiline():
+    text = ".animate[\n![Phil](images/phil.jpeg)\n]"
+    result = convert_class_wrappers(text)
+    assert '<div class="animate">' in result
+    assert "![Phil](images/phil.jpeg)" in result
+
+
+def test_convert_class_wrappers_nested_brackets():
+    text = ".big[text with [link](url)]"
+    result = convert_class_wrappers(text)
+    assert "[link](url)" in result
+
+
+def test_no_class_wrappers():
+    text = "Just normal markdown"
+    result = convert_class_wrappers(text)
+    assert result == "Just normal markdown"
+```
+
+- [ ] **Step 2: Run tests to verify they fail**
+
+Run: `python -m pytest tests/test_preprocessor.py -v -k "class_wrappers"`
+Expected: FAIL — `ImportError`
+
+- [ ] **Step 3: Implement `convert_class_wrappers`**
+
+Add to `preprocessor.py`:
+```python
+def convert_class_wrappers(text: str) -> str:
+    """Convert .classname[content] remark syntax to HTML elements.
+
+    Block-level usage (line starts with .classname[) becomes <div class="...">.
+    Inline usage becomes <span class="...">.
+    Handles nested brackets (e.g., markdown links inside wrappers).
+    Handles multiline blocks where ] is on a subsequent line.
+    """
+    result = _convert_multiline_wrappers(text)
+    result = _convert_inline_wrappers(result)
+    return result
+
+
+def _convert_multiline_wrappers(text: str) -> str:
+    """Handle .classname[...] that spans multiple lines."""
+    lines = text.split("\n")
+    result = []
+    i = 0
+
+    while i < len(lines):
+        match = re.match(r"^\.(\w[\w-]*)\[\s*$", lines[i].strip())
+        if match:
+            classname = match.group(1)
+            # Collect lines until we find a closing ]
+            inner_lines = []
+            i += 1
+            while i < len(lines) and lines[i].strip() != "]":
+                inner_lines.append(lines[i])
+                i += 1
+            inner = "\n".join(inner_lines).strip()
+            result.append(f'<div class="{classname}" markdown="1">\n\n{inner}\n\n</div>')
+            i += 1  # Skip the closing ]
+        else:
+            result.append(lines[i])
+            i += 1
+
+    return "\n".join(result)
+
+
+def _convert_inline_wrappers(text: str) -> str:
+    """Handle .classname[...] on a single line."""
+    # Pattern: .classname[ at start of line (block) or inline
+    def replace_match(match):
+        classname = match.group(1)
+        content = match.group(2)
+        line_before = match.string[:match.start()]
+        line_after = match.string[match.end():]
+
+        # Block-level only if .classname[...] is the entire line content:
+        # nothing before it (on this line) and nothing after it (on this line)
+        last_newline = line_before.rfind("\n")
+        line_start = line_before[last_newline + 1:] if last_newline >= 0 else line_before
+
+        next_newline = line_after.find("\n")
+        line_end = line_after[:next_newline] if next_newline >= 0 else line_after
+
+        if line_start.strip() == "" and line_end.strip() == "":
+            # Block-level: use markdown="1" so python-markdown renders inner content
+            return f'<div class="{classname}" markdown="1">\n\n{content}\n\n</div>'
+        else:
+            return f'<span class="{classname}">{content}</span>'
+
+    # Match .classname[content] handling nested brackets
+    pattern = r"\.(\w[\w-]*)\[((?:[^\[\]]*|\[(?:[^\[\]]*|\[[^\[\]]*\])*\])*)\]"
+    return re.sub(pattern, replace_match, text)
+```
+
+- [ ] **Step 4: Run tests to verify they pass**
+
+Run: `python -m pytest tests/test_preprocessor.py -v -k "class_wrappers"`
+Expected: All 7 tests PASS.
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add preprocessor.py tests/test_preprocessor.py
+git commit -m "add .classname[content] wrapper conversion"
+```
+
+---
+
+### Task 6: Full Preprocessing Pipeline
+
+**Files:**
+- Modify: `preprocessor.py`
+- Modify: `tests/test_preprocessor.py`
+
+- [ ] **Step 1: Write failing test for the combined pipeline**
+
+Append to `tests/test_preprocessor.py`:
+```python
+from preprocessor import process_slide
+
+
+def test_process_slide_full():
+    slide = """class: center, middle
+# Title
+.big[**Important**]
+
+--
+
+More content
+
+???
+
+Speaker notes here"""
+    html_content, classes = process_slide(slide)
+    assert classes == ["center", "middle"]
+    assert "Speaker notes" not in html_content
+    assert "Important" in html_content
+    assert "More content" in html_content
+    assert "???" not in html_content
+    assert '<span class="big">' in html_content or '<div class="big">' in html_content
+```
+
+- [ ] **Step 2: Run test to verify it fails**
+
+Run: `python -m pytest tests/test_preprocessor.py::test_process_slide_full -v`
+Expected: FAIL — `ImportError`
+
+- [ ] **Step 3: Implement `process_slide`**
+
+Add to `preprocessor.py`:
+```python
+import markdown
+
+
+def process_slide(slide_md: str) -> tuple[str, list[str]]:
+    """Full preprocessing pipeline for a single slide.
+
+    Returns (rendered_html, css_classes).
+    """
+    # 1. Extract class directive
+    content, classes = strip_class_directive(slide_md)
+
+    # 2. Strip presenter notes
+    content = strip_presenter_notes(content)
+
+    # 3. Strip incremental reveals
+    content = strip_incremental_reveals(content)
+
+    # 4. Convert .classname[] wrappers
+    content = convert_class_wrappers(content)
+
+    # 5. Render markdown to HTML
+    # md_in_html extension allows markdown inside <div markdown="1"> blocks
+    # produced by convert_class_wrappers for block-level .classname[] usage
+    md = markdown.Markdown(
+        extensions=["fenced_code", "codehilite", "tables", "md_in_html"],
+        extension_configs={
+            "codehilite": {"css_class": "highlight", "guess_lang": False}
+        },
+    )
+    html = md.convert(content)
+
+    return html, classes
+```
+
+- [ ] **Step 4: Run tests to verify they pass**
+
+Run: `python -m pytest tests/test_preprocessor.py -v`
+Expected: All tests PASS.
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add preprocessor.py tests/test_preprocessor.py
+git commit -m "add full slide preprocessing pipeline"
+```
+
+---
+
+### Task 7: Image Path Rewriting
+
+**Files:**
+- Modify: `preprocessor.py`
+- Modify: `tests/test_preprocessor.py`
+
+- [ ] **Step 1: Write failing tests**
+
+Append to `tests/test_preprocessor.py`:
+```python
+from preprocessor import rewrite_image_paths
+
+
+def test_rewrite_relative_image_paths():
+    html = '<img alt="Photo" src="images/photo.png" />'
+    result = rewrite_image_paths(html)
+    assert 'src="/lecture_notes/images/photo.png"' in result
+
+
+def test_rewrite_leaves_absolute_paths():
+    html = '<img alt="Photo" src="/examples/week_1/image.png" />'
+    result = rewrite_image_paths(html)
+    assert 'src="/examples/week_1/image.png"' in result
+
+
+def test_rewrite_leaves_external_urls():
+    html = '<img alt="Comic" src="https://imgs.xkcd.com/comics/exploits.png" />'
+    result = rewrite_image_paths(html)
+    assert 'src="https://imgs.xkcd.com/comics/exploits.png"' in result
+
+
+def test_rewrite_does_not_touch_script_src():
+    html = '<script src="navigation.js"></script>'
+    result = rewrite_image_paths(html)
+    assert result == html
+```
+
+- [ ] **Step 2: Run tests to verify they fail**
+
+Run: `python -m pytest tests/test_preprocessor.py -v -k "rewrite"`
+Expected: FAIL — `ImportError`
+
+- [ ] **Step 3: Implement `rewrite_image_paths`**
+
+Add to `preprocessor.py`:
+```python
+def rewrite_image_paths(html: str) -> str:
+    """Rewrite relative image src paths to absolute /lecture_notes/ paths.
+    Only affects <img> tags, not <script> or other elements.
+    """
+    def replace_img_src(match):
+        prefix = match.group(1)
+        src = match.group(2)
+        if src.startswith(("http://", "https://", "/")):
+            return match.group(0)
+        return f'<img{prefix}src="/lecture_notes/{src}"'
+
+    return re.sub(r'<img([^>]*)src="([^"]*)"', replace_img_src, html)
+```
+
+- [ ] **Step 4: Run tests to verify they pass**
+
+Run: `python -m pytest tests/test_preprocessor.py -v -k "rewrite"`
+Expected: All 4 tests PASS.
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add preprocessor.py tests/test_preprocessor.py
+git commit -m "add image path rewriting for slide output"
+```
+
+---
+
+### Task 8: Jinja2 Templates
+
+**Files:**
+- Create: `templates/base.html`
+- Create: `templates/slide.html`
+- Create: `templates/page.html`
+- Create: `templates/index.html`
+- Create: `templates/lecture_index.html`
+
+- [ ] **Step 1: Create `templates/base.html`**
+
+```html
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="utf-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1">
+    <title>{% block title %}Web Development{% endblock %}</title>
+    <link rel="stylesheet" href="/css/style.css">
+</head>
+<body>
+    <nav id="header">
+        <ul>
+            <li><a href="/">Home</a></li>
+            <li><a href="/lecture_notes/">Lectures</a></li>
+            <li><a href="/syllabus/">Syllabus</a></li>
+            <li><a href="/examples/">Examples</a></li>
+        </ul>
+    </nav>
+    <main>
+        {% block content %}{% endblock %}
+    </main>
+    {% block scripts %}{% endblock %}
+</body>
+</html>
+```
+
+- [ ] **Step 2: Create `templates/slide.html`**
+
+```html
+{% extends "base.html" %}
+
+{% block title %}Week {{ week }} — Slide {{ slide_num }} | Web Development{% endblock %}
+
+{% block content %}
+<div class="slide-container {{ classes|join(' ') }}"
+     data-prev="{{ prev_url }}"
+     data-next="{{ next_url }}"
+     data-first="{{ first_url }}"
+     data-slide-num="{{ slide_num }}"
+     data-total-slides="{{ total_slides }}"
+     data-week="{{ week }}">
+
+    <div class="slide-nav">
+        {% if prev_url %}
+        <a href="{{ prev_url }}" class="nav-prev" aria-label="Previous slide">&larr;</a>
+        {% else %}
+        <span class="nav-prev disabled">&larr;</span>
+        {% endif %}
+
+        <span class="slide-info">Week {{ week }} &mdash; {{ slide_num }} / {{ total_slides }}</span>
+
+        {% if next_url %}
+        <a href="{{ next_url }}" class="nav-next" aria-label="Next slide">&rarr;</a>
+        {% else %}
+        <span class="nav-next disabled">&rarr;</span>
+        {% endif %}
+    </div>
+
+    <div class="slide-content">
+        {{ content }}
+    </div>
+</div>
+{% endblock %}
+
+{% block scripts %}
+<script src="/js/navigation.js"></script>
+{% endblock %}
+```
+
+- [ ] **Step 3: Create `templates/page.html`**
+
+```html
+{% extends "base.html" %}
+
+{% block title %}{{ title }} | Web Development{% endblock %}
+
+{% block content %}
+<div class="page-content">
+    {{ content }}
+</div>
+{% endblock %}
+```
+
+- [ ] **Step 4: Create `templates/index.html`**
+
+```html
+{% extends "base.html" %}
+
+{% block title %}Web Development — MPCS 52553{% endblock %}
+
+{% block content %}
+<div class="homepage">
+    <h1>Web Development</h1>
+    <h3>MPCS 52553 — Spring 2026</h3>
+    <ul>
+        <li><a href="/syllabus/">Syllabus</a></li>
+        <li><a href="/lecture_notes/">Lecture Notes</a></li>
+        <li><a href="/examples/">Examples &amp; Labs</a></li>
+    </ul>
+    <p>
+        Course materials are on
+        <a href="https://github.com/UChicagoWebDev">GitHub</a>.
+        Join <strong>#web-development</strong> on
+        <a href="https://cs-uchicago.slack.com/">UChicago CS Slack</a>.
+    </p>
+</div>
+{% endblock %}
+```
+
+- [ ] **Step 5: Create `templates/lecture_index.html`**
+
+```html
+{% extends "base.html" %}
+
+{% block title %}Lecture Notes | Web Development{% endblock %}
+
+{% block content %}
+<div class="lecture-index">
+    <h1>Lecture Notes</h1>
+    <p>
+        Lecture notes are written in
+        <a href="https://docs.github.com/en/get-started/writing-on-github/getting-started-with-writing-and-formatting-on-github/basic-writing-and-formatting-syntax">Markdown</a>
+        and can also be found
+        <a href="https://github.com/UChicagoWebDev/course_materials/tree/main/lecture_notes">in the Course Materials repo on GitHub</a>.
+    </p>
+    <ul>
+        {% for week in weeks %}
+        <li><a href="/lecture_notes/week_{{ week }}/1/">Week {{ week }}</a></li>
+        {% endfor %}
+    </ul>
+</div>
+{% endblock %}
+```
+
+- [ ] **Step 6: Commit**
+
+```bash
+git add templates/
+git commit -m "add Jinja2 templates for slides, pages, and indexes"
+```
+
+---
+
+### Task 9: CSS Stylesheet
+
+**Files:**
+- Create: `static/css/style.css`
+
+- [ ] **Step 1: Create `static/css/style.css`**
+
+Port relevant rules from `lecture_notes/styles/style.css`, replacing `.remark-*` selectors with new structure. Key sections:
+
+```css
+/* Fonts */
+@import url(https://fonts.googleapis.com/css?family=Yanone+Kaffeesatz);
+@import url(https://fonts.googleapis.com/css?family=Droid+Serif:400,700,400italic);
+@import url(https://fonts.googleapis.com/css?family=Droid+Sans:400,700,400italic);
+@import url(https://fonts.googleapis.com/css?family=Ubuntu+Mono:400,700,400italic);
+
+/* Base */
+body {
+    font-family: "Droid Serif", serif;
+    background-color: white;
+    margin: 0;
+    min-width: 15em;
+}
+
+/* Navigation header */
+#header {
+    background-color: #333;
+    font-family: "Droid Sans", sans-serif;
+    padding: 0;
+}
+#header ul {
+    display: flex;
+    margin: 0;
+    padding: 0;
+    list-style: none;
+}
+#header li {
+    padding: 0.25em 0.75em;
+}
+#header a, #header a:visited {
+    color: white;
+    text-decoration: none;
+}
+#header a:hover {
+    color: #ccc;
+}
+
+/* Slide navigation bar */
+.slide-nav {
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    padding: 0.5em;
+    gap: 1em;
+    font-family: "Droid Sans", sans-serif;
+    border-bottom: 1px solid #eee;
+}
+.slide-nav a {
+    text-decoration: none;
+    color: #333;
+    font-size: 1.5em;
+}
+.slide-nav .disabled {
+    color: #ccc;
+}
+.slide-info {
+    font-size: 0.9em;
+    color: #666;
+}
+
+/* Slide content area */
+.slide-container {
+    max-width: 960px;
+    margin: 0 auto;
+    padding: 1em 2em;
+}
+.slide-content {
+    padding: 1em 0;
+}
+
+/* Page content (syllabus, etc.) */
+.page-content {
+    max-width: 960px;
+    margin: 0 auto;
+    padding: 1em 2em;
+}
+
+/* Homepage */
+.homepage {
+    max-width: 960px;
+    margin: 0 auto;
+    padding: 2em;
+}
+
+/* Lecture index */
+.lecture-index {
+    max-width: 960px;
+    margin: 0 auto;
+    padding: 1em 2em;
+}
+
+/* Typography */
+h1, h2, h3 {
+    font-family: "Yanone Kaffeesatz", sans-serif;
+    font-weight: normal;
+}
+
+/* Remark class ports */
+.center { text-align: center; }
+.middle { display: flex; flex-direction: column; justify-content: center; min-height: 60vh; }
+
+.big { font-size: xx-large; font-family: "Yanone Kaffeesatz", sans-serif; }
+.fancyStrong strong { font-size: xx-large; font-family: "Yanone Kaffeesatz", sans-serif; }
+
+.credit {
+    display: block;
+    color: #aaa;
+    text-decoration: none;
+    font-size: 0.75em;
+    text-align: center;
+    padding: 0.25em;
+}
+.credit a { color: #aaa; }
+
+.half img { max-width: 40%; max-height: 40%; }
+
+.split ul {
+    list-style-type: none;
+    display: flex;
+    padding: 0;
+}
+.split ul li {
+    width: auto;
+    max-width: 70%;
+}
+.split ul li img { max-width: 100%; }
+
+.agenda h1 { margin-bottom: 0; }
+.agenda ul { margin-block-start: 0; color: #666; }
+
+.overlay p { position: relative; z-index: 1; padding: 1em; background: rgba(255,255,255,0.8); }
+.overlay p:has(img) { z-index: 0; width: 100%; float: right; margin-bottom: -100%; }
+
+.gallery p:has(img) { display: flex; flex-wrap: wrap; justify-content: center; }
+.gallery p:has(img) img { height: 8em; margin: 1em; }
+
+.gallery-big p:has(img) { display: flex; flex-wrap: wrap; justify-content: center; }
+.gallery-big p:has(img) img { height: 16em; margin: 1em; }
+
+.animate img {
+    width: 210px;
+    animation-duration: 3s;
+    animation-name: rise;
+}
+@keyframes rise {
+    from { margin-top: 60%; margin-left: 100%; }
+    to { margin-top: 0%; }
+}
+
+.highlight-third-code-line .highlight pre code .line:nth-child(3) {
+    font-weight: bold;
+}
+
+/* Images */
+img {
+    display: block;
+    max-width: 80%;
+    max-height: 80%;
+}
+
+/* Blockquotes */
+blockquote p {
+    border-left: 0.5em solid lightgray;
+    padding-left: 0.5em;
+}
+blockquote footer {
+    font-size: small;
+    color: gray;
+}
+
+/* Code blocks */
+code, pre {
+    font-family: "Ubuntu Mono", monospace;
+}
+code {
+    background-color: lightblue;
+    padding: 2px 5px;
+}
+pre code {
+    display: block;
+    padding: 1em;
+    overflow-x: auto;
+}
+```
+
+- [ ] **Step 2: Commit**
+
+```bash
+mkdir -p static/css
+git add static/css/style.css
+git commit -m "add site stylesheet ported from remark CSS"
+```
+
+---
+
+### Task 10: Navigation JavaScript
+
+**Files:**
+- Create: `static/js/navigation.js`
+
+- [ ] **Step 1: Create `static/js/navigation.js`**
+
+```javascript
+document.addEventListener("DOMContentLoaded", function () {
+    const container = document.querySelector(".slide-container");
+    if (!container) return;
+
+    const prevUrl = container.dataset.prev;
+    const nextUrl = container.dataset.next;
+    const firstUrl = container.dataset.first;
+
+    document.addEventListener("keydown", function (e) {
+        // Don't navigate if user is typing in an input
+        if (e.target.tagName === "INPUT" || e.target.tagName === "TEXTAREA") return;
+
+        switch (e.key) {
+            case "ArrowRight":
+            case "ArrowDown":
+                if (nextUrl) window.location.href = nextUrl;
+                break;
+            case "ArrowLeft":
+            case "ArrowUp":
+                if (prevUrl) window.location.href = prevUrl;
+                break;
+            case "Home":
+                if (firstUrl) window.location.href = firstUrl;
+                e.preventDefault();
+                break;
+        }
+    });
+});
+```
+
+- [ ] **Step 2: Commit**
+
+```bash
+mkdir -p static/js
+git add static/js/navigation.js
+git commit -m "add keyboard navigation for slides"
+```
+
+---
+
+### Task 11: Build Script
+
+**Files:**
+- Create: `build.py`
+- Create: `tests/test_build.py`
+
+- [ ] **Step 1: Write integration test**
+
+`tests/test_build.py`:
+```python
+import os
+import shutil
+from pathlib import Path
+from build import build_site
+
+
+def test_build_produces_output(tmp_path, monkeypatch):
+    """Smoke test: build produces _site/ with expected structure."""
+    monkeypatch.chdir(Path(__file__).parent.parent)
+    build_site(output_dir=str(tmp_path / "_site"))
+    site = tmp_path / "_site"
+
+    assert (site / "index.html").exists()
+    assert (site / "syllabus" / "index.html").exists()
+    assert (site / "lecture_notes" / "index.html").exists()
+    assert (site / "lecture_notes" / "week_1" / "1" / "index.html").exists()
+    assert (site / "css" / "style.css").exists()
+    assert (site / "js" / "navigation.js").exists()
+    assert (site / "examples").is_dir()
+    assert (site / "lecture_notes" / "images").is_dir()
+
+
+def test_build_slide_has_navigation(tmp_path, monkeypatch):
+    """Slide pages include navigation data attributes."""
+    monkeypatch.chdir(Path(__file__).parent.parent)
+    build_site(output_dir=str(tmp_path / "_site"))
+
+    slide = (tmp_path / "_site" / "lecture_notes" / "week_1" / "2" / "index.html").read_text()
+    assert 'data-prev=' in slide
+    assert 'data-next=' in slide
+    assert 'data-slide-num="2"' in slide
+
+
+def test_build_no_week_8_old(tmp_path, monkeypatch):
+    """week_8_old.md should not produce output."""
+    monkeypatch.chdir(Path(__file__).parent.parent)
+    build_site(output_dir=str(tmp_path / "_site"))
+
+    assert not (tmp_path / "_site" / "lecture_notes" / "week_8_old").exists()
+```
+
+- [ ] **Step 2: Run tests to verify they fail**
+
+Run: `python -m pytest tests/test_build.py -v`
+Expected: FAIL — `ImportError: cannot import name 'build_site'`
+
+- [ ] **Step 3: Implement `build.py`**
+
+```python
+import glob
+import os
+import re
+import shutil
+from pathlib import Path
+
+from jinja2 import Environment, FileSystemLoader
+import markdown
+
+from preprocessor import split_slides, process_slide, rewrite_image_paths
+
+
+def build_site(output_dir: str = "_site"):
+    """Build the entire static site."""
+    root = Path(__file__).parent
+    out = Path(output_dir)
+
+    # Clean output
+    if out.exists():
+        shutil.rmtree(out)
+    out.mkdir(parents=True)
+
+    # Set up Jinja2
+    env = Environment(loader=FileSystemLoader(root / "templates"))
+
+    # Copy static assets
+    shutil.copytree(root / "static" / "css", out / "css")
+    shutil.copytree(root / "static" / "js", out / "js")
+    shutil.copytree(root / "examples", out / "examples")
+    shutil.copytree(root / "lecture_notes" / "images", out / "lecture_notes" / "images")
+
+    # Find week files (exclude _old files)
+    week_files = sorted(glob.glob(str(root / "lecture_notes" / "week_*.md")))
+    week_files = [f for f in week_files if "_old" not in f]
+
+    weeks = []
+
+    for week_file in week_files:
+        week_num = int(re.search(r"week_(\d+)", week_file).group(1))
+        weeks.append(week_num)
+
+        md_content = Path(week_file).read_text()
+        slide_strings = split_slides(md_content)
+
+        total_slides = len(slide_strings)
+        week_dir = out / "lecture_notes" / f"week_{week_num}"
+
+        for i, slide_md in enumerate(slide_strings, 1):
+            html_content, classes = process_slide(slide_md)
+            html_content = rewrite_image_paths(html_content)
+
+            prev_url = f"/lecture_notes/week_{week_num}/{i - 1}/" if i > 1 else ""
+            next_url = f"/lecture_notes/week_{week_num}/{i + 1}/" if i < total_slides else ""
+            first_url = f"/lecture_notes/week_{week_num}/1/"
+
+            slide_html = env.get_template("slide.html").render(
+                content=html_content,
+                classes=classes,
+                week=week_num,
+                slide_num=i,
+                total_slides=total_slides,
+                prev_url=prev_url,
+                next_url=next_url,
+                first_url=first_url,
+            )
+
+            slide_dir = week_dir / str(i)
+            slide_dir.mkdir(parents=True, exist_ok=True)
+            (slide_dir / "index.html").write_text(slide_html)
+
+    # Lecture notes index
+    lecture_index_html = env.get_template("lecture_index.html").render(weeks=weeks)
+    lectures_dir = out / "lecture_notes"
+    lectures_dir.mkdir(parents=True, exist_ok=True)
+    (lectures_dir / "index.html").write_text(lecture_index_html)
+
+    # Syllabus
+    syllabus_md = (root / "syllabus.md").read_text()
+    md_renderer = markdown.Markdown(
+        extensions=["fenced_code", "codehilite", "tables"],
+        extension_configs={
+            "codehilite": {"css_class": "highlight", "guess_lang": False}
+        },
+    )
+    syllabus_html = md_renderer.convert(syllabus_md)
+    page_html = env.get_template("page.html").render(
+        title="Syllabus", content=syllabus_html
+    )
+    syllabus_dir = out / "syllabus"
+    syllabus_dir.mkdir(parents=True, exist_ok=True)
+    (syllabus_dir / "index.html").write_text(page_html)
+
+    # Homepage
+    homepage_html = env.get_template("index.html").render()
+    (out / "index.html").write_text(homepage_html)
+
+
+if __name__ == "__main__":
+    build_site()
+```
+
+- [ ] **Step 4: Run tests to verify they pass**
+
+Run: `python -m pytest tests/test_build.py -v`
+Expected: All 3 tests PASS.
+
+- [ ] **Step 5: Run full build and check output**
+
+Run: `python build.py && python -m http.server -d _site 8080 &`
+
+Manually verify:
+- `http://localhost:8080/` — homepage loads
+- `http://localhost:8080/lecture_notes/` — week listing
+- `http://localhost:8080/lecture_notes/week_1/1/` — first slide, arrow keys work
+- `http://localhost:8080/syllabus/` — syllabus renders
+- `http://localhost:8080/examples/` — examples directory listing
+- Images display correctly on slides
+
+- [ ] **Step 6: Add `_site/` to `.gitignore`**
+
+Append to `.gitignore`:
+```
+_site/
+```
+
+- [ ] **Step 7: Commit**
+
+```bash
+git add build.py tests/test_build.py .gitignore
+git commit -m "add build script for static site generation"
+```
+
+---
+
+### Task 12: GitHub Actions Workflow
+
+**Files:**
+- Create: `.github/workflows/build-and-deploy.yml`
+
+- [ ] **Step 1: Create workflow file**
+
+`.github/workflows/build-and-deploy.yml`:
+```yaml
+name: Build and Deploy
+
+on:
+  push:
+    branches: [main]
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+concurrency:
+  group: "pages"
+  cancel-in-progress: false
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+      - run: pip install -r requirements.txt
+      - run: python build.py
+      - uses: actions/upload-pages-artifact@v3
+        with:
+          path: _site
+
+  deploy:
+    needs: build
+    runs-on: ubuntu-latest
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    steps:
+      - id: deployment
+        uses: actions/deploy-pages@v4
+```
+
+- [ ] **Step 2: Commit**
+
+```bash
+git add .github/workflows/build-and-deploy.yml
+git commit -m "add GitHub Actions workflow for Pages deployment"
+```
+
+---
+
+### Task 13: End-to-End Verification
+
+- [ ] **Step 1: Run all tests**
+
+Run: `python -m pytest tests/ -v`
+Expected: All tests pass.
+
+- [ ] **Step 2: Build the site**
+
+Run: `python build.py`
+Expected: `_site/` directory created with all expected files.
+
+- [ ] **Step 3: Manual browser check**
+
+Run: `python -m http.server -d _site 8080`
+
+Check:
+- Homepage renders and links work
+- Lecture notes index lists all weeks
+- Slides render with correct content (no remark syntax visible)
+- Keyboard navigation works (arrow keys, Home)
+- Images display correctly
+- Code blocks have syntax highlighting
+- Syllabus page renders
+- Examples directory is browsable
+- CSS classes from remark (`.big`, `.half`, `.credit`, `.split`, etc.) render correctly
+
+- [ ] **Step 4: Stop server, final commit if any fixes needed**

From c454919faf32913997fdf04daf920d84d093a9b6 Mon Sep 17 00:00:00 2001
From: Trevor Austin <trevor@tavernresearch.com>
Date: Wed, 1 Apr 2026 14:29:20 -0500
Subject: [PATCH 03/16] add .worktrees/ to .gitignore

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 .gitignore | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/.gitignore b/.gitignore
index 36ed094..bcbbe5e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,5 @@
 .DS_Store
 apikey.js
 *.pyc
-*/__pycache__/*
\ No newline at end of file
+*/__pycache__/*
+.worktrees/
\ No newline at end of file

From 1aa1bc7af70169f80c47f8e02520c07fdb35b364 Mon Sep 17 00:00:00 2001
From: Trevor Austin <trevor@tavernresearch.com>
Date: Wed, 1 Apr 2026 14:32:24 -0500
Subject: [PATCH 04/16] add project scaffolding for static site generator

---
 requirements.txt  | 3 +++
 tests/__init__.py | 0
 2 files changed, 3 insertions(+)
 create mode 100644 requirements.txt
 create mode 100644 tests/__init__.py

diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 0000000..c89c25d
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1,3 @@
+Jinja2>=3.1
+Markdown>=3.5
+Pygments>=2.17
diff --git a/tests/__init__.py b/tests/__init__.py
new file mode 100644
index 0000000..e69de29

From a218b1eabd71543e145cc43c9bc4fad37bf5ac60 Mon Sep 17 00:00:00 2001
From: Trevor Austin <trevor@tavernresearch.com>
Date: Wed, 1 Apr 2026 14:33:31 -0500
Subject: [PATCH 05/16] add slide splitting with fenced code block awareness

---
 preprocessor.py            | 76 ++++++++++++++++++++++++++++++++++++++
 tests/test_preprocessor.py | 23 ++++++++++++
 2 files changed, 99 insertions(+)
 create mode 100644 preprocessor.py
 create mode 100644 tests/test_preprocessor.py

diff --git a/preprocessor.py b/preprocessor.py
new file mode 100644
index 0000000..289c365
--- /dev/null
+++ b/preprocessor.py
@@ -0,0 +1,76 @@
+import re
+
+
+def split_slides(markdown: str) -> list[str]:
+    """Split markdown on --- slide boundaries, ignoring --- inside fenced code blocks."""
+    slides = []
+    current_slide = []
+    in_code_block = False
+
+    for line in markdown.split("\n"):
+        stripped = line.strip()
+
+        if stripped.startswith("```"):
+            in_code_block = not in_code_block
+
+        if stripped == "---" and not in_code_block:
+            slides.append("\n".join(current_slide))
+            current_slide = []
+        else:
+            current_slide.append(line)
+
+    if current_slide:
+        slides.append("\n".join(current_slide))
+
+    return [s.strip() for s in slides if s.strip()]
+
+
+def strip_class_directive(slide: str) -> tuple[str, list[str]]:
+    """Remove 'class: ...' directive from top of slide. Returns (content, class_list)."""
+    lines = slide.split("\n")
+    if lines and lines[0].strip().startswith("class:"):
+        class_line = lines[0].strip()
+        class_str = class_line[len("class:"):].strip()
+        classes = [c.strip() for c in class_str.split(",")]
+        return "\n".join(lines[1:]), classes
+    return slide, []
+
+
+def strip_presenter_notes(slide: str) -> str:
+    """Remove everything from a standalone ??? line to end of slide, outside code blocks."""
+    lines = slide.split("\n")
+    result = []
+    in_code_block = False
+
+    for line in lines:
+        stripped = line.strip()
+
+        if stripped.startswith("```"):
+            in_code_block = not in_code_block
+
+        if stripped == "???" and not in_code_block:
+            break
+
+        result.append(line)
+
+    return "\n".join(result).rstrip()
+
+
+def strip_incremental_reveals(slide: str) -> str:
+    """Remove standalone -- lines (incremental reveal markers) outside code blocks."""
+    lines = slide.split("\n")
+    result = []
+    in_code_block = False
+
+    for line in lines:
+        stripped = line.strip()
+
+        if stripped.startswith("```"):
+            in_code_block = not in_code_block
+
+        if stripped == "--" and not in_code_block:
+            continue
+
+        result.append(line)
+
+    return "\n".join(result)
diff --git a/tests/test_preprocessor.py b/tests/test_preprocessor.py
new file mode 100644
index 0000000..cb2f867
--- /dev/null
+++ b/tests/test_preprocessor.py
@@ -0,0 +1,23 @@
+from preprocessor import split_slides
+
+
+def test_split_slides_basic():
+    md = "# Slide 1\nContent\n---\n# Slide 2\nMore content"
+    slides = split_slides(md)
+    assert len(slides) == 2
+    assert "# Slide 1" in slides[0]
+    assert "# Slide 2" in slides[1]
+
+
+def test_split_slides_ignores_hr_in_code_block():
+    md = "# Slide 1\n```\n---\n```\n---\n# Slide 2"
+    slides = split_slides(md)
+    assert len(slides) == 2
+    assert "---" in slides[0]
+
+
+def test_split_slides_trims_whitespace():
+    md = "# Slide 1\n\n---\n\n# Slide 2\n"
+    slides = split_slides(md)
+    assert slides[0].strip() == "# Slide 1"
+    assert slides[1].strip() == "# Slide 2"

From fea1c26d4c6304e51b05958bcdca1b241918cff7 Mon Sep 17 00:00:00 2001
From: Trevor Austin <trevor@tavernresearch.com>
Date: Wed, 1 Apr 2026 16:54:10 -0500
Subject: [PATCH 06/16] add strip_class_directive with tests

---
 tests/test_preprocessor.py | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/tests/test_preprocessor.py b/tests/test_preprocessor.py
index cb2f867..cab112b 100644
--- a/tests/test_preprocessor.py
+++ b/tests/test_preprocessor.py
@@ -1,4 +1,4 @@
-from preprocessor import split_slides
+from preprocessor import split_slides, strip_class_directive
 
 
 def test_split_slides_basic():
@@ -21,3 +21,24 @@ def test_split_slides_trims_whitespace():
     slides = split_slides(md)
     assert slides[0].strip() == "# Slide 1"
     assert slides[1].strip() == "# Slide 2"
+
+
+def test_strip_class_directive_basic():
+    slide = "class: center, middle\n# Title"
+    content, classes = strip_class_directive(slide)
+    assert content.strip() == "# Title"
+    assert classes == ["center", "middle"]
+
+
+def test_strip_class_directive_none():
+    slide = "# No class here"
+    content, classes = strip_class_directive(slide)
+    assert content.strip() == "# No class here"
+    assert classes == []
+
+
+def test_strip_class_directive_single():
+    slide = "class: agenda\n# Agenda Items"
+    content, classes = strip_class_directive(slide)
+    assert content.strip() == "# Agenda Items"
+    assert classes == ["agenda"]

From c4fe9822f79d5a4218b4df594c4adc50f4b9236d Mon Sep 17 00:00:00 2001
From: Trevor Austin <trevor@tavernresearch.com>
Date: Wed, 1 Apr 2026 16:56:49 -0500
Subject: [PATCH 07/16] add strip_presenter_notes and strip_incremental_reveals
 with tests

---
 tests/test_preprocessor.py | 37 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

diff --git a/tests/test_preprocessor.py b/tests/test_preprocessor.py
index cab112b..b27ddf1 100644
--- a/tests/test_preprocessor.py
+++ b/tests/test_preprocessor.py
@@ -1,4 +1,4 @@
-from preprocessor import split_slides, strip_class_directive
+from preprocessor import split_slides, strip_class_directive, strip_presenter_notes, strip_incremental_reveals
 
 
 def test_split_slides_basic():
@@ -42,3 +42,38 @@ def test_strip_class_directive_single():
     content, classes = strip_class_directive(slide)
     assert content.strip() == "# Agenda Items"
     assert classes == ["agenda"]
+
+
+def test_strip_presenter_notes_basic():
+    slide = "# Slide\nContent\n\n???\n\nThese are notes"
+    result = strip_presenter_notes(slide)
+    assert "Content" in result
+    assert "notes" not in result
+    assert "???" not in result
+
+
+def test_strip_presenter_notes_no_notes():
+    slide = "# Slide\nContent"
+    result = strip_presenter_notes(slide)
+    assert result == slide
+
+
+def test_strip_presenter_notes_ignores_code_block():
+    slide = "# Slide\n```\n???\n```\nMore content"
+    result = strip_presenter_notes(slide)
+    assert "???" in result
+    assert "More content" in result
+
+
+def test_strip_incremental_reveals():
+    slide = "# Slide\nFirst point\n\n--\n\nSecond point"
+    result = strip_incremental_reveals(slide)
+    assert "First point" in result
+    assert "Second point" in result
+    assert "\n--\n" not in result
+
+
+def test_strip_incremental_reveals_ignores_code_block():
+    slide = "```\n--\n```"
+    result = strip_incremental_reveals(slide)
+    assert "--" in result

From c82882da849bd09def2f9c25e8ed899d6d811792 Mon Sep 17 00:00:00 2001
From: Trevor Austin <trevor@tavernresearch.com>
Date: Wed, 1 Apr 2026 17:08:49 -0500
Subject: [PATCH 08/16] add .classname[content] wrapper conversion

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 preprocessor.py            | 65 ++++++++++++++++++++++++++++++++++++++
 tests/test_preprocessor.py | 46 ++++++++++++++++++++++++++-
 2 files changed, 110 insertions(+), 1 deletion(-)

diff --git a/preprocessor.py b/preprocessor.py
index 289c365..e04e7b9 100644
--- a/preprocessor.py
+++ b/preprocessor.py
@@ -74,3 +74,68 @@ def strip_incremental_reveals(slide: str) -> str:
         result.append(line)
 
     return "\n".join(result)
+
+
+def convert_class_wrappers(text: str) -> str:
+    """Convert .classname[content] remark syntax to HTML elements.
+
+    Block-level usage (line starts with .classname[) becomes <div class="...">.
+    Inline usage becomes <span class="...">.
+    Handles nested brackets (e.g., markdown links inside wrappers).
+    Handles multiline blocks where ] is on a subsequent line.
+    """
+    result = _convert_multiline_wrappers(text)
+    result = _convert_inline_wrappers(result)
+    return result
+
+
+def _convert_multiline_wrappers(text: str) -> str:
+    """Handle .classname[...] that spans multiple lines."""
+    lines = text.split("\n")
+    result = []
+    i = 0
+
+    while i < len(lines):
+        match = re.match(r"^\.(\w[\w-]*)\[\s*$", lines[i].strip())
+        if match:
+            classname = match.group(1)
+            inner_lines = []
+            i += 1
+            while i < len(lines) and lines[i].strip() != "]":
+                inner_lines.append(lines[i])
+                i += 1
+            inner = "\n".join(inner_lines).strip()
+            result.append(f'<div class="{classname}" markdown="1">\n\n{inner}\n\n</div>')
+            i += 1  # Skip the closing ]
+        else:
+            result.append(lines[i])
+            i += 1
+
+    return "\n".join(result)
+
+
+def _convert_inline_wrappers(text: str) -> str:
+    """Handle .classname[...] on a single line."""
+    def replace_match(match):
+        classname = match.group(1)
+        content = match.group(2)
+        line_before = match.string[:match.start()]
+        line_after = match.string[match.end():]
+
+        # Block-level only if .classname[...] is the entire line content:
+        # nothing before it (on this line) and nothing after it (on this line)
+        last_newline = line_before.rfind("\n")
+        line_start = line_before[last_newline + 1:] if last_newline >= 0 else line_before
+
+        next_newline = line_after.find("\n")
+        line_end = line_after[:next_newline] if next_newline >= 0 else line_after
+
+        if line_start.strip() == "" and line_end.strip() == "":
+            # Block-level: use markdown="1" so python-markdown renders inner content
+            return f'<div class="{classname}" markdown="1">\n\n{content}\n\n</div>'
+        else:
+            return f'<span class="{classname}">{content}</span>'
+
+    # Match .classname[content] handling nested brackets
+    pattern = r"\.(\w[\w-]*)\[((?:[^\[\]]*|\[(?:[^\[\]]*|\[[^\[\]]*\])*\])*)\]"
+    return re.sub(pattern, replace_match, text)
diff --git a/tests/test_preprocessor.py b/tests/test_preprocessor.py
index b27ddf1..5b2cb37 100644
--- a/tests/test_preprocessor.py
+++ b/tests/test_preprocessor.py
@@ -1,4 +1,4 @@
-from preprocessor import split_slides, strip_class_directive, strip_presenter_notes, strip_incremental_reveals
+from preprocessor import split_slides, strip_class_directive, strip_presenter_notes, strip_incremental_reveals, convert_class_wrappers
 
 
 def test_split_slides_basic():
@@ -77,3 +77,47 @@ def test_strip_incremental_reveals_ignores_code_block():
     slide = "```\n--\n```"
     result = strip_incremental_reveals(slide)
     assert "--" in result
+
+
+def test_convert_class_wrappers_inline():
+    text = "Some .big[**bold text**] here"
+    result = convert_class_wrappers(text)
+    assert result == 'Some <span class="big">**bold text**</span> here'
+
+
+def test_convert_class_wrappers_line_start_with_trailing_text():
+    """A .classname[] at line start with trailing text is inline, not block."""
+    text = ".big[**0.1 second**] is about the limit for the user"
+    result = convert_class_wrappers(text)
+    assert result == '<span class="big">**0.1 second**</span> is about the limit for the user'
+
+
+def test_convert_class_wrappers_block_whole_line():
+    text = ".half[![Image](foo.png)]"
+    result = convert_class_wrappers(text)
+    assert result == '<div class="half" markdown="1">\n\n![Image](foo.png)\n\n</div>'
+
+
+def test_convert_class_wrappers_credit():
+    text = ".credit[https://xkcd.com/327/]"
+    result = convert_class_wrappers(text)
+    assert result == '<div class="credit" markdown="1">\n\nhttps://xkcd.com/327/\n\n</div>'
+
+
+def test_convert_class_wrappers_multiline():
+    text = ".animate[\n![Phil](images/phil.jpeg)\n]"
+    result = convert_class_wrappers(text)
+    assert '<div class="animate"' in result
+    assert "![Phil](images/phil.jpeg)" in result
+
+
+def test_convert_class_wrappers_nested_brackets():
+    text = ".big[text with [link](url)]"
+    result = convert_class_wrappers(text)
+    assert "[link](url)" in result
+
+
+def test_no_class_wrappers():
+    text = "Just normal markdown"
+    result = convert_class_wrappers(text)
+    assert result == "Just normal markdown"

From 4232223d6e79436a921f62fb7ab7fa7bd15cf609 Mon Sep 17 00:00:00 2001
From: Trevor Austin <trevor@tavernresearch.com>
Date: Wed, 1 Apr 2026 17:16:44 -0500
Subject: [PATCH 09/16] add full slide preprocessing pipeline

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 preprocessor.py            | 33 +++++++++++++++++++++++++++++++++
 tests/test_preprocessor.py | 23 ++++++++++++++++++++++-
 2 files changed, 55 insertions(+), 1 deletion(-)

diff --git a/preprocessor.py b/preprocessor.py
index e04e7b9..9424d80 100644
--- a/preprocessor.py
+++ b/preprocessor.py
@@ -1,5 +1,7 @@
 import re
 
+import markdown
+
 
 def split_slides(markdown: str) -> list[str]:
     """Split markdown on --- slide boundaries, ignoring --- inside fenced code blocks."""
@@ -139,3 +141,34 @@ def replace_match(match):
     # Match .classname[content] handling nested brackets
     pattern = r"\.(\w[\w-]*)\[((?:[^\[\]]*|\[(?:[^\[\]]*|\[[^\[\]]*\])*\])*)\]"
     return re.sub(pattern, replace_match, text)
+
+
+def process_slide(slide_md: str) -> tuple[str, list[str]]:
+    """Full preprocessing pipeline for a single slide.
+
+    Returns (rendered_html, css_classes).
+    """
+    # 1. Extract class directive
+    content, classes = strip_class_directive(slide_md)
+
+    # 2. Strip presenter notes
+    content = strip_presenter_notes(content)
+
+    # 3. Strip incremental reveals
+    content = strip_incremental_reveals(content)
+
+    # 4. Convert .classname[] wrappers
+    content = convert_class_wrappers(content)
+
+    # 5. Render markdown to HTML
+    # md_in_html extension allows markdown inside <div markdown="1"> blocks
+    # produced by convert_class_wrappers for block-level .classname[] usage
+    md = markdown.Markdown(
+        extensions=["fenced_code", "codehilite", "tables", "md_in_html"],
+        extension_configs={
+            "codehilite": {"css_class": "highlight", "guess_lang": False}
+        },
+    )
+    html = md.convert(content)
+
+    return html, classes
diff --git a/tests/test_preprocessor.py b/tests/test_preprocessor.py
index 5b2cb37..99271d0 100644
--- a/tests/test_preprocessor.py
+++ b/tests/test_preprocessor.py
@@ -1,4 +1,4 @@
-from preprocessor import split_slides, strip_class_directive, strip_presenter_notes, strip_incremental_reveals, convert_class_wrappers
+from preprocessor import split_slides, strip_class_directive, strip_presenter_notes, strip_incremental_reveals, convert_class_wrappers, process_slide
 
 
 def test_split_slides_basic():
@@ -121,3 +121,24 @@ def test_no_class_wrappers():
     text = "Just normal markdown"
     result = convert_class_wrappers(text)
     assert result == "Just normal markdown"
+
+
+def test_process_slide_full():
+    slide = """class: center, middle
+# Title
+.big[**Important**]
+
+--
+
+More content
+
+???
+
+Speaker notes here"""
+    html_content, classes = process_slide(slide)
+    assert classes == ["center", "middle"]
+    assert "Speaker notes" not in html_content
+    assert "Important" in html_content
+    assert "More content" in html_content
+    assert "???" not in html_content
+    assert '<span class="big">' in html_content or '<div class="big">' in html_content

From 7a5d762ac9dd64167e2298add8234862121e69ce Mon Sep 17 00:00:00 2001
From: Trevor Austin <trevor@tavernresearch.com>
Date: Wed, 1 Apr 2026 17:17:12 -0500
Subject: [PATCH 10/16] add image path rewriting for slide output

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 preprocessor.py            | 14 ++++++++++++++
 tests/test_preprocessor.py | 26 +++++++++++++++++++++++++-
 2 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/preprocessor.py b/preprocessor.py
index 9424d80..3e80f16 100644
--- a/preprocessor.py
+++ b/preprocessor.py
@@ -172,3 +172,17 @@ def process_slide(slide_md: str) -> tuple[str, list[str]]:
     html = md.convert(content)
 
     return html, classes
+
+
+def rewrite_image_paths(html: str) -> str:
+    """Rewrite relative image src paths to absolute /lecture_notes/ paths.
+    Only affects <img> tags, not <script> or other elements.
+    """
+    def replace_img_src(match):
+        prefix = match.group(1)
+        src = match.group(2)
+        if src.startswith(("http://", "https://", "/")):
+            return match.group(0)
+        return f'<img{prefix}src="/lecture_notes/{src}"'
+
+    return re.sub(r'<img([^>]*)src="([^"]*)"', replace_img_src, html)
diff --git a/tests/test_preprocessor.py b/tests/test_preprocessor.py
index 99271d0..e2216be 100644
--- a/tests/test_preprocessor.py
+++ b/tests/test_preprocessor.py
@@ -1,4 +1,4 @@
-from preprocessor import split_slides, strip_class_directive, strip_presenter_notes, strip_incremental_reveals, convert_class_wrappers, process_slide
+from preprocessor import split_slides, strip_class_directive, strip_presenter_notes, strip_incremental_reveals, convert_class_wrappers, process_slide, rewrite_image_paths
 
 
 def test_split_slides_basic():
@@ -142,3 +142,27 @@ def test_process_slide_full():
     assert "More content" in html_content
     assert "???" not in html_content
     assert '<span class="big">' in html_content or '<div class="big">' in html_content
+
+
+def test_rewrite_relative_image_paths():
+    html = '<img alt="Photo" src="images/photo.png" />'
+    result = rewrite_image_paths(html)
+    assert 'src="/lecture_notes/images/photo.png"' in result
+
+
+def test_rewrite_leaves_absolute_paths():
+    html = '<img alt="Photo" src="/examples/week_1/image.png" />'
+    result = rewrite_image_paths(html)
+    assert 'src="/examples/week_1/image.png"' in result
+
+
+def test_rewrite_leaves_external_urls():
+    html = '<img alt="Comic" src="https://imgs.xkcd.com/comics/exploits.png" />'
+    result = rewrite_image_paths(html)
+    assert 'src="https://imgs.xkcd.com/comics/exploits.png"' in result
+
+
+def test_rewrite_does_not_touch_script_src():
+    html = '<script src="navigation.js"></script>'
+    result = rewrite_image_paths(html)
+    assert result == html

From 5f65e15b746de7866eef9d0a7275c2fb9673d7a9 Mon Sep 17 00:00:00 2001
From: Trevor Austin <trevor@tavernresearch.com>
Date: Wed, 1 Apr 2026 17:18:40 -0500
Subject: [PATCH 11/16] add Jinja2 templates for slides, pages, and indexes

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 templates/base.html          | 23 ++++++++++++++++++++++
 templates/index.html         | 21 ++++++++++++++++++++
 templates/lecture_index.html | 20 +++++++++++++++++++
 templates/page.html          |  9 +++++++++
 templates/slide.html         | 38 ++++++++++++++++++++++++++++++++++++
 5 files changed, 111 insertions(+)
 create mode 100644 templates/base.html
 create mode 100644 templates/index.html
 create mode 100644 templates/lecture_index.html
 create mode 100644 templates/page.html
 create mode 100644 templates/slide.html

diff --git a/templates/base.html b/templates/base.html
new file mode 100644
index 0000000..5489469
--- /dev/null
+++ b/templates/base.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="utf-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1">
+    <title>{% block title %}Web Development{% endblock %}</title>
+    <link rel="stylesheet" href="/css/style.css">
+</head>
+<body>
+    <nav id="header">
+        <ul>
+            <li><a href="/">Home</a></li>
+            <li><a href="/lecture_notes/">Lectures</a></li>
+            <li><a href="/syllabus/">Syllabus</a></li>
+            <li><a href="/examples/">Examples</a></li>
+        </ul>
+    </nav>
+    <main>
+        {% block content %}{% endblock %}
+    </main>
+    {% block scripts %}{% endblock %}
+</body>
+</html>
diff --git a/templates/index.html b/templates/index.html
new file mode 100644
index 0000000..9456470
--- /dev/null
+++ b/templates/index.html
@@ -0,0 +1,21 @@
+{% extends "base.html" %}
+
+{% block title %}Web Development — MPCS 52553{% endblock %}
+
+{% block content %}
+<div class="homepage">
+    <h1>Web Development</h1>
+    <h3>MPCS 52553 — Spring 2026</h3>
+    <ul>
+        <li><a href="/syllabus/">Syllabus</a></li>
+        <li><a href="/lecture_notes/">Lecture Notes</a></li>
+        <li><a href="/examples/">Examples &amp; Labs</a></li>
+    </ul>
+    <p>
+        Course materials are on
+        <a href="https://github.com/UChicagoWebDev">GitHub</a>.
+        Join <strong>#web-development</strong> on
+        <a href="https://cs-uchicago.slack.com/">UChicago CS Slack</a>.
+    </p>
+</div>
+{% endblock %}
diff --git a/templates/lecture_index.html b/templates/lecture_index.html
new file mode 100644
index 0000000..435a71a
--- /dev/null
+++ b/templates/lecture_index.html
@@ -0,0 +1,20 @@
+{% extends "base.html" %}
+
+{% block title %}Lecture Notes | Web Development{% endblock %}
+
+{% block content %}
+<div class="lecture-index">
+    <h1>Lecture Notes</h1>
+    <p>
+        Lecture notes are written in
+        <a href="https://docs.github.com/en/get-started/writing-on-github/getting-started-with-writing-and-formatting-on-github/basic-writing-and-formatting-syntax">Markdown</a>
+        and can also be found
+        <a href="https://github.com/UChicagoWebDev/course_materials/tree/main/lecture_notes">in the Course Materials repo on GitHub</a>.
+    </p>
+    <ul>
+        {% for week in weeks %}
+        <li><a href="/lecture_notes/week_{{ week }}/1/">Week {{ week }}</a></li>
+        {% endfor %}
+    </ul>
+</div>
+{% endblock %}
diff --git a/templates/page.html b/templates/page.html
new file mode 100644
index 0000000..56d3742
--- /dev/null
+++ b/templates/page.html
@@ -0,0 +1,9 @@
+{% extends "base.html" %}
+
+{% block title %}{{ title }} | Web Development{% endblock %}
+
+{% block content %}
+<div class="page-content">
+    {{ content }}
+</div>
+{% endblock %}
diff --git a/templates/slide.html b/templates/slide.html
new file mode 100644
index 0000000..9cdecd0
--- /dev/null
+++ b/templates/slide.html
@@ -0,0 +1,38 @@
+{% extends "base.html" %}
+
+{% block title %}Week {{ week }} — Slide {{ slide_num }} | Web Development{% endblock %}
+
+{% block content %}
+<div class="slide-container {{ classes|join(' ') }}"
+     data-prev="{{ prev_url }}"
+     data-next="{{ next_url }}"
+     data-first="{{ first_url }}"
+     data-slide-num="{{ slide_num }}"
+     data-total-slides="{{ total_slides }}"
+     data-week="{{ week }}">
+
+    <div class="slide-nav">
+        {% if prev_url %}
+        <a href="{{ prev_url }}" class="nav-prev" aria-label="Previous slide">&larr;</a>
+        {% else %}
+        <span class="nav-prev disabled">&larr;</span>
+        {% endif %}
+
+        <span class="slide-info">Week {{ week }} &mdash; {{ slide_num }} / {{ total_slides }}</span>
+
+        {% if next_url %}
+        <a href="{{ next_url }}" class="nav-next" aria-label="Next slide">&rarr;</a>
+        {% else %}
+        <span class="nav-next disabled">&rarr;</span>
+        {% endif %}
+    </div>
+
+    <div class="slide-content">
+        {{ content }}
+    </div>
+</div>
+{% endblock %}
+
+{% block scripts %}
+<script src="/js/navigation.js"></script>
+{% endblock %}

From c8ad3de394b3358b9d0f2b5862448e7984a3fc12 Mon Sep 17 00:00:00 2001
From: Trevor Austin <trevor@tavernresearch.com>
Date: Wed, 1 Apr 2026 17:18:44 -0500
Subject: [PATCH 12/16] add keyboard navigation for slides

---
 static/js/navigation.js | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)
 create mode 100644 static/js/navigation.js

diff --git a/static/js/navigation.js b/static/js/navigation.js
new file mode 100644
index 0000000..8d4ef46
--- /dev/null
+++ b/static/js/navigation.js
@@ -0,0 +1,28 @@
+document.addEventListener("DOMContentLoaded", function () {
+    const container = document.querySelector(".slide-container");
+    if (!container) return;
+
+    const prevUrl = container.dataset.prev;
+    const nextUrl = container.dataset.next;
+    const firstUrl = container.dataset.first;
+
+    document.addEventListener("keydown", function (e) {
+        // Don't navigate if user is typing in an input
+        if (e.target.tagName === "INPUT" || e.target.tagName === "TEXTAREA") return;
+
+        switch (e.key) {
+            case "ArrowRight":
+            case "ArrowDown":
+                if (nextUrl) window.location.href = nextUrl;
+                break;
+            case "ArrowLeft":
+            case "ArrowUp":
+                if (prevUrl) window.location.href = prevUrl;
+                break;
+            case "Home":
+                if (firstUrl) window.location.href = firstUrl;
+                e.preventDefault();
+                break;
+        }
+    });
+});

From 9e0c25d724c2df85545d9c9930a92de1fcb6271c Mon Sep 17 00:00:00 2001
From: Trevor Austin <trevor@tavernresearch.com>
Date: Wed, 1 Apr 2026 17:18:54 -0500
Subject: [PATCH 13/16] add site stylesheet ported from remark CSS

---
 static/css/style.css | 183 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 183 insertions(+)
 create mode 100644 static/css/style.css

diff --git a/static/css/style.css b/static/css/style.css
new file mode 100644
index 0000000..e8e3e24
--- /dev/null
+++ b/static/css/style.css
@@ -0,0 +1,183 @@
+/* Fonts */
+@import url(https://fonts.googleapis.com/css?family=Yanone+Kaffeesatz);
+@import url(https://fonts.googleapis.com/css?family=Droid+Serif:400,700,400italic);
+@import url(https://fonts.googleapis.com/css?family=Droid+Sans:400,700,400italic);
+@import url(https://fonts.googleapis.com/css?family=Ubuntu+Mono:400,700,400italic);
+
+/* Base */
+body {
+    font-family: "Droid Serif", serif;
+    background-color: white;
+    margin: 0;
+    min-width: 15em;
+}
+
+/* Navigation header */
+#header {
+    background-color: #333;
+    font-family: "Droid Sans", sans-serif;
+    padding: 0;
+}
+#header ul {
+    display: flex;
+    margin: 0;
+    padding: 0;
+    list-style: none;
+}
+#header li {
+    padding: 0.25em 0.75em;
+}
+#header a, #header a:visited {
+    color: white;
+    text-decoration: none;
+}
+#header a:hover {
+    color: #ccc;
+}
+
+/* Slide navigation bar */
+.slide-nav {
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    padding: 0.5em;
+    gap: 1em;
+    font-family: "Droid Sans", sans-serif;
+    border-bottom: 1px solid #eee;
+}
+.slide-nav a {
+    text-decoration: none;
+    color: #333;
+    font-size: 1.5em;
+}
+.slide-nav .disabled {
+    color: #ccc;
+}
+.slide-info {
+    font-size: 0.9em;
+    color: #666;
+}
+
+/* Slide content area */
+.slide-container {
+    max-width: 960px;
+    margin: 0 auto;
+    padding: 1em 2em;
+}
+.slide-content {
+    padding: 1em 0;
+}
+
+/* Page content (syllabus, etc.) */
+.page-content {
+    max-width: 960px;
+    margin: 0 auto;
+    padding: 1em 2em;
+}
+
+/* Homepage */
+.homepage {
+    max-width: 960px;
+    margin: 0 auto;
+    padding: 2em;
+}
+
+/* Lecture index */
+.lecture-index {
+    max-width: 960px;
+    margin: 0 auto;
+    padding: 1em 2em;
+}
+
+/* Typography */
+h1, h2, h3 {
+    font-family: "Yanone Kaffeesatz", sans-serif;
+    font-weight: normal;
+}
+
+/* Remark class ports */
+.center { text-align: center; }
+.middle { display: flex; flex-direction: column; justify-content: center; min-height: 60vh; }
+
+.big { font-size: xx-large; font-family: "Yanone Kaffeesatz", sans-serif; }
+.fancyStrong strong { font-size: xx-large; font-family: "Yanone Kaffeesatz", sans-serif; }
+
+.credit {
+    display: block;
+    color: #aaa;
+    text-decoration: none;
+    font-size: 0.75em;
+    text-align: center;
+    padding: 0.25em;
+}
+.credit a { color: #aaa; }
+
+.half img { max-width: 40%; max-height: 40%; }
+
+.split ul {
+    list-style-type: none;
+    display: flex;
+    padding: 0;
+}
+.split ul li {
+    width: auto;
+    max-width: 70%;
+}
+.split ul li img { max-width: 100%; }
+
+.agenda h1 { margin-bottom: 0; }
+.agenda ul { margin-block-start: 0; color: #666; }
+
+.overlay p { position: relative; z-index: 1; padding: 1em; background: rgba(255,255,255,0.8); }
+.overlay p:has(img) { z-index: 0; width: 100%; float: right; margin-bottom: -100%; }
+
+.gallery p:has(img) { display: flex; flex-wrap: wrap; justify-content: center; }
+.gallery p:has(img) img { height: 8em; margin: 1em; }
+
+.gallery-big p:has(img) { display: flex; flex-wrap: wrap; justify-content: center; }
+.gallery-big p:has(img) img { height: 16em; margin: 1em; }
+
+.animate img {
+    width: 210px;
+    animation-duration: 3s;
+    animation-name: rise;
+}
+@keyframes rise {
+    from { margin-top: 60%; margin-left: 100%; }
+    to { margin-top: 0%; }
+}
+
+.highlight-third-code-line .highlight pre code .line:nth-child(3) {
+    font-weight: bold;
+}
+
+/* Images */
+img {
+    display: block;
+    max-width: 80%;
+    max-height: 80%;
+}
+
+/* Blockquotes */
+blockquote p {
+    border-left: 0.5em solid lightgray;
+    padding-left: 0.5em;
+}
+blockquote footer {
+    font-size: small;
+    color: gray;
+}
+
+/* Code blocks */
+code, pre {
+    font-family: "Ubuntu Mono", monospace;
+}
+code {
+    background-color: lightblue;
+    padding: 2px 5px;
+}
+pre code {
+    display: block;
+    padding: 1em;
+    overflow-x: auto;
+}

From be8ad57adb6e17c49205f56615400f506d403e17 Mon Sep 17 00:00:00 2001
From: Trevor Austin <trevor@tavernresearch.com>
Date: Thu, 2 Apr 2026 09:41:20 -0500
Subject: [PATCH 14/16] add build script for static site generation

Integrates preprocessor, Jinja2 templates, CSS, and JS into a complete
build pipeline that reads markdown lecture notes and produces a static
site in _site/. Includes integration tests and adds _site/ to .gitignore.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 .gitignore          |   3 +-
 build.py            | 100 ++++++++++++++++++++++++++++++++++++++++++++
 tests/test_build.py |  39 +++++++++++++++++
 3 files changed, 141 insertions(+), 1 deletion(-)
 create mode 100644 build.py
 create mode 100644 tests/test_build.py

diff --git a/.gitignore b/.gitignore
index bcbbe5e..83ced5b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,4 +2,5 @@
 apikey.js
 *.pyc
 */__pycache__/*
-.worktrees/
\ No newline at end of file
+.worktrees/
+_site/
\ No newline at end of file
diff --git a/build.py b/build.py
new file mode 100644
index 0000000..176e44c
--- /dev/null
+++ b/build.py
@@ -0,0 +1,100 @@
+import glob
+import os
+import re
+import shutil
+from pathlib import Path
+
+from jinja2 import Environment, FileSystemLoader
+import markdown
+
+from preprocessor import split_slides, process_slide, rewrite_image_paths
+
+
+def build_site(output_dir: str = "_site"):
+    """Build the entire static site."""
+    root = Path(__file__).parent
+    out = Path(output_dir)
+
+    # Clean output
+    if out.exists():
+        shutil.rmtree(out)
+    out.mkdir(parents=True)
+
+    # Set up Jinja2 — autoescape=False since templates use {{ content }}
+    # with pre-rendered HTML and this is a static site generator, not a web app
+    env = Environment(loader=FileSystemLoader(root / "templates"), autoescape=False)
+
+    # Copy static assets
+    shutil.copytree(root / "static" / "css", out / "css")
+    shutil.copytree(root / "static" / "js", out / "js")
+    shutil.copytree(root / "examples", out / "examples")
+    shutil.copytree(root / "lecture_notes" / "images", out / "lecture_notes" / "images")
+
+    # Find week files (exclude _old files)
+    week_files = sorted(glob.glob(str(root / "lecture_notes" / "week_*.md")))
+    week_files = [f for f in week_files if "_old" not in f]
+
+    weeks = []
+
+    for week_file in week_files:
+        week_num = int(re.search(r"week_(\d+)", week_file).group(1))
+        weeks.append(week_num)
+
+        md_content = Path(week_file).read_text()
+        slide_strings = split_slides(md_content)
+
+        total_slides = len(slide_strings)
+        week_dir = out / "lecture_notes" / f"week_{week_num}"
+
+        for i, slide_md in enumerate(slide_strings, 1):
+            html_content, classes = process_slide(slide_md)
+            html_content = rewrite_image_paths(html_content)
+
+            prev_url = f"/lecture_notes/week_{week_num}/{i - 1}/" if i > 1 else ""
+            next_url = f"/lecture_notes/week_{week_num}/{i + 1}/" if i < total_slides else ""
+            first_url = f"/lecture_notes/week_{week_num}/1/"
+
+            slide_html = env.get_template("slide.html").render(
+                content=html_content,
+                classes=classes,
+                week=week_num,
+                slide_num=i,
+                total_slides=total_slides,
+                prev_url=prev_url,
+                next_url=next_url,
+                first_url=first_url,
+            )
+
+            slide_dir = week_dir / str(i)
+            slide_dir.mkdir(parents=True, exist_ok=True)
+            (slide_dir / "index.html").write_text(slide_html)
+
+    # Lecture notes index
+    lecture_index_html = env.get_template("lecture_index.html").render(weeks=weeks)
+    lectures_dir = out / "lecture_notes"
+    lectures_dir.mkdir(parents=True, exist_ok=True)
+    (lectures_dir / "index.html").write_text(lecture_index_html)
+
+    # Syllabus
+    syllabus_md = (root / "syllabus.md").read_text()
+    md_renderer = markdown.Markdown(
+        extensions=["fenced_code", "codehilite", "tables"],
+        extension_configs={
+            "codehilite": {"css_class": "highlight", "guess_lang": False}
+        },
+    )
+    syllabus_html = md_renderer.convert(syllabus_md)
+    page_html = env.get_template("page.html").render(
+        title="Syllabus", content=syllabus_html
+    )
+    syllabus_dir = out / "syllabus"
+    syllabus_dir.mkdir(parents=True, exist_ok=True)
+    (syllabus_dir / "index.html").write_text(page_html)
+
+    # Homepage
+    homepage_html = env.get_template("index.html").render()
+    (out / "index.html").write_text(homepage_html)
+
+
+if __name__ == "__main__":
+    build_site()
diff --git a/tests/test_build.py b/tests/test_build.py
new file mode 100644
index 0000000..3678ee2
--- /dev/null
+++ b/tests/test_build.py
@@ -0,0 +1,39 @@
+import os
+import shutil
+from pathlib import Path
+from build import build_site
+
+
+def test_build_produces_output(tmp_path, monkeypatch):
+    """Smoke test: build produces _site/ with expected structure."""
+    monkeypatch.chdir(Path(__file__).parent.parent)
+    build_site(output_dir=str(tmp_path / "_site"))
+    site = tmp_path / "_site"
+
+    assert (site / "index.html").exists()
+    assert (site / "syllabus" / "index.html").exists()
+    assert (site / "lecture_notes" / "index.html").exists()
+    assert (site / "lecture_notes" / "week_1" / "1" / "index.html").exists()
+    assert (site / "css" / "style.css").exists()
+    assert (site / "js" / "navigation.js").exists()
+    assert (site / "examples").is_dir()
+    assert (site / "lecture_notes" / "images").is_dir()
+
+
+def test_build_slide_has_navigation(tmp_path, monkeypatch):
+    """Slide pages include navigation data attributes."""
+    monkeypatch.chdir(Path(__file__).parent.parent)
+    build_site(output_dir=str(tmp_path / "_site"))
+
+    slide = (tmp_path / "_site" / "lecture_notes" / "week_1" / "2" / "index.html").read_text()
+    assert 'data-prev=' in slide
+    assert 'data-next=' in slide
+    assert 'data-slide-num="2"' in slide
+
+
+def test_build_no_week_8_old(tmp_path, monkeypatch):
+    """week_8_old.md should not produce output."""
+    monkeypatch.chdir(Path(__file__).parent.parent)
+    build_site(output_dir=str(tmp_path / "_site"))
+
+    assert not (tmp_path / "_site" / "lecture_notes" / "week_8_old").exists()

From 677d47d9517d7ad97fa79636b8b7ba9bda00bd54 Mon Sep 17 00:00:00 2001
From: Trevor Austin <trevor@tavernresearch.com>
Date: Thu, 2 Apr 2026 09:42:30 -0500
Subject: [PATCH 15/16] add GitHub Actions workflow for Pages deployment

---
 .github/workflows/build-and-deploy.yml | 39 ++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)
 create mode 100644 .github/workflows/build-and-deploy.yml

diff --git a/.github/workflows/build-and-deploy.yml b/.github/workflows/build-and-deploy.yml
new file mode 100644
index 0000000..4e7d0e9
--- /dev/null
+++ b/.github/workflows/build-and-deploy.yml
@@ -0,0 +1,39 @@
+name: Build and Deploy
+
+on:
+  push:
+    branches: [main]
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+concurrency:
+  group: "pages"
+  cancel-in-progress: false
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+      - run: pip install -r requirements.txt
+      - run: python build.py
+      - uses: actions/upload-pages-artifact@v3
+        with:
+          path: _site
+
+  deploy:
+    needs: build
+    runs-on: ubuntu-latest
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    steps:
+      - id: deployment
+        uses: actions/deploy-pages@v4

From 825d27e3002822f0607b23ea042abada8b5a6036 Mon Sep 17 00:00:00 2001
From: Trevor Austin <trevor@tavernresearch.com>
Date: Fri, 3 Apr 2026 12:20:06 -0500
Subject: [PATCH 16/16] add base_url support for GitHub Pages project sites

All internal links were hardcoded to the domain root (/css/...,
/lecture_notes/..., etc.), which breaks on project sites served at a
subpath like /course_materials/. Threads a --base-url CLI arg through
build.py, Jinja2 globals, and image path rewriting.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 .github/workflows/build-and-deploy.yml |  2 +-
 build.py                               | 28 ++++++++++++++++++--------
 preprocessor.py                        |  4 ++--
 templates/base.html                    | 10 ++++-----
 templates/index.html                   |  6 +++---
 templates/lecture_index.html           |  2 +-
 templates/slide.html                   |  2 +-
 tests/test_build.py                    | 23 +++++++++++++++++++--
 8 files changed, 54 insertions(+), 23 deletions(-)

diff --git a/.github/workflows/build-and-deploy.yml b/.github/workflows/build-and-deploy.yml
index 4e7d0e9..97db00d 100644
--- a/.github/workflows/build-and-deploy.yml
+++ b/.github/workflows/build-and-deploy.yml
@@ -23,7 +23,7 @@ jobs:
         with:
           python-version: "3.12"
       - run: pip install -r requirements.txt
-      - run: python build.py
+      - run: python build.py --base-url "/${{ github.event.repository.name }}"
       - uses: actions/upload-pages-artifact@v3
         with:
           path: _site
diff --git a/build.py b/build.py
index 176e44c..00dc940 100644
--- a/build.py
+++ b/build.py
@@ -1,5 +1,5 @@
+import argparse
 import glob
-import os
 import re
 import shutil
 from pathlib import Path
@@ -10,8 +10,12 @@
 from preprocessor import split_slides, process_slide, rewrite_image_paths
 
 
-def build_site(output_dir: str = "_site"):
-    """Build the entire static site."""
+def build_site(output_dir: str = "_site", base_url: str = ""):
+    """Build the entire static site.
+
+    base_url: path prefix for project sites (e.g., "/course_materials").
+              Empty string for sites served at the domain root.
+    """
     root = Path(__file__).parent
     out = Path(output_dir)
 
@@ -23,6 +27,7 @@ def build_site(output_dir: str = "_site"):
     # Set up Jinja2 — autoescape=False since templates use {{ content }}
     # with pre-rendered HTML and this is a static site generator, not a web app
     env = Environment(loader=FileSystemLoader(root / "templates"), autoescape=False)
+    env.globals["base_url"] = base_url
 
     # Copy static assets
     shutil.copytree(root / "static" / "css", out / "css")
@@ -48,11 +53,11 @@ def build_site(output_dir: str = "_site"):
 
         for i, slide_md in enumerate(slide_strings, 1):
             html_content, classes = process_slide(slide_md)
-            html_content = rewrite_image_paths(html_content)
+            html_content = rewrite_image_paths(html_content, base_url)
 
-            prev_url = f"/lecture_notes/week_{week_num}/{i - 1}/" if i > 1 else ""
-            next_url = f"/lecture_notes/week_{week_num}/{i + 1}/" if i < total_slides else ""
-            first_url = f"/lecture_notes/week_{week_num}/1/"
+            prev_url = f"{base_url}/lecture_notes/week_{week_num}/{i - 1}/" if i > 1 else ""
+            next_url = f"{base_url}/lecture_notes/week_{week_num}/{i + 1}/" if i < total_slides else ""
+            first_url = f"{base_url}/lecture_notes/week_{week_num}/1/"
 
             slide_html = env.get_template("slide.html").render(
                 content=html_content,
@@ -97,4 +102,11 @@ def build_site(output_dir: str = "_site"):
 
 
 if __name__ == "__main__":
-    build_site()
+    parser = argparse.ArgumentParser(description="Build the static site.")
+    parser.add_argument(
+        "--base-url",
+        default="",
+        help="URL path prefix for project sites (e.g., /course_materials)",
+    )
+    args = parser.parse_args()
+    build_site(base_url=args.base_url.rstrip("/"))
diff --git a/preprocessor.py b/preprocessor.py
index 3e80f16..1f43e6a 100644
--- a/preprocessor.py
+++ b/preprocessor.py
@@ -174,7 +174,7 @@ def process_slide(slide_md: str) -> tuple[str, list[str]]:
     return html, classes
 
 
-def rewrite_image_paths(html: str) -> str:
+def rewrite_image_paths(html: str, base_url: str = "") -> str:
     """Rewrite relative image src paths to absolute /lecture_notes/ paths.
     Only affects <img> tags, not <script> or other elements.
     """
@@ -183,6 +183,6 @@ def replace_img_src(match):
         src = match.group(2)
         if src.startswith(("http://", "https://", "/")):
             return match.group(0)
-        return f'<img{prefix}src="/lecture_notes/{src}"'
+        return f'<img{prefix}src="{base_url}/lecture_notes/{src}"'
 
     return re.sub(r'<img([^>]*)src="([^"]*)"', replace_img_src, html)
diff --git a/templates/base.html b/templates/base.html
index 5489469..cac5f73 100644
--- a/templates/base.html
+++ b/templates/base.html
@@ -4,15 +4,15 @@
     <meta charset="utf-8">
     <meta name="viewport" content="width=device-width, initial-scale=1">
     <title>{% block title %}Web Development{% endblock %}</title>
-    <link rel="stylesheet" href="/css/style.css">
+    <link rel="stylesheet" href="{{ base_url }}/css/style.css">
 </head>
 <body>
     <nav id="header">
         <ul>
-            <li><a href="/">Home</a></li>
-            <li><a href="/lecture_notes/">Lectures</a></li>
-            <li><a href="/syllabus/">Syllabus</a></li>
-            <li><a href="/examples/">Examples</a></li>
+            <li><a href="{{ base_url }}/">Home</a></li>
+            <li><a href="{{ base_url }}/lecture_notes/">Lectures</a></li>
+            <li><a href="{{ base_url }}/syllabus/">Syllabus</a></li>
+            <li><a href="{{ base_url }}/examples/">Examples</a></li>
         </ul>
     </nav>
     <main>
diff --git a/templates/index.html b/templates/index.html
index 9456470..b597d76 100644
--- a/templates/index.html
+++ b/templates/index.html
@@ -7,9 +7,9 @@
     <h1>Web Development</h1>
     <h3>MPCS 52553 — Spring 2026</h3>
     <ul>
-        <li><a href="/syllabus/">Syllabus</a></li>
-        <li><a href="/lecture_notes/">Lecture Notes</a></li>
-        <li><a href="/examples/">Examples &amp; Labs</a></li>
+        <li><a href="{{ base_url }}/syllabus/">Syllabus</a></li>
+        <li><a href="{{ base_url }}/lecture_notes/">Lecture Notes</a></li>
+        <li><a href="{{ base_url }}/examples/">Examples &amp; Labs</a></li>
     </ul>
     <p>
         Course materials are on
diff --git a/templates/lecture_index.html b/templates/lecture_index.html
index 435a71a..235815a 100644
--- a/templates/lecture_index.html
+++ b/templates/lecture_index.html
@@ -13,7 +13,7 @@ <h1>Lecture Notes</h1>
     </p>
     <ul>
         {% for week in weeks %}
-        <li><a href="/lecture_notes/week_{{ week }}/1/">Week {{ week }}</a></li>
+        <li><a href="{{ base_url }}/lecture_notes/week_{{ week }}/1/">Week {{ week }}</a></li>
         {% endfor %}
     </ul>
 </div>
diff --git a/templates/slide.html b/templates/slide.html
index 9cdecd0..6350458 100644
--- a/templates/slide.html
+++ b/templates/slide.html
@@ -34,5 +34,5 @@
 {% endblock %}
 
 {% block scripts %}
-<script src="/js/navigation.js"></script>
+<script src="{{ base_url }}/js/navigation.js"></script>
 {% endblock %}
diff --git a/tests/test_build.py b/tests/test_build.py
index 3678ee2..df0f595 100644
--- a/tests/test_build.py
+++ b/tests/test_build.py
@@ -1,5 +1,3 @@
-import os
-import shutil
 from pathlib import Path
 from build import build_site
 
@@ -37,3 +35,24 @@ def test_build_no_week_8_old(tmp_path, monkeypatch):
     build_site(output_dir=str(tmp_path / "_site"))
 
     assert not (tmp_path / "_site" / "lecture_notes" / "week_8_old").exists()
+
+
+def test_build_base_url(tmp_path, monkeypatch):
+    """base_url is prefixed on all internal links."""
+    monkeypatch.chdir(Path(__file__).parent.parent)
+    build_site(output_dir=str(tmp_path / "_site"), base_url="/course_materials")
+    site = tmp_path / "_site"
+
+    # Homepage links use base_url
+    homepage = (site / "index.html").read_text()
+    assert 'href="/course_materials/syllabus/"' in homepage
+
+    # Slide navigation uses base_url
+    slide = (site / "lecture_notes" / "week_1" / "2" / "index.html").read_text()
+    assert 'data-prev="/course_materials/lecture_notes/week_1/1/"' in slide
+    assert "/course_materials/js/navigation.js" in slide
+    assert "/course_materials/css/style.css" in slide
+
+    # Lecture index uses base_url
+    lecture_index = (site / "lecture_notes" / "index.html").read_text()
+    assert "/course_materials/lecture_notes/week_1/1/" in lecture_index