Phase 4: implement full static site (Eleventy, 15 pages, CSS, JS)

specification/02-architecture-decisions.md

@@ -66,6 +66,25 @@ This file records stable architectural decisions and their rationale. Items here
   - Each grouped page must contain enough unique content to serve its target keywords
   - Internal linking from the Services hub must cover all sub-topics
 
+## ADR-006 — Static site generator: Eleventy (11ty)
+- **Status**: Accepted
+- **Context**: The site has 15+ pages sharing a common nav, footer, and layout. Plain HTML would require copy-pasting these into every file, creating a maintenance burden when nav items change.
+- **Decision**: Use **Eleventy 2.x** (`@11ty/eleventy`) as the static site generator with **Nunjucks** as the template language.
+- **Rationale**:
+  - Produces pure static HTML files — no runtime dependency
+  - Nunjucks layout chaining and includes eliminate nav/footer duplication
+  - Simple data cascade for service pages (frontmatter-driven)
+  - Well-documented, widely used for exactly this use case
+  - `npm run build` outputs to `_site/` which Caddy serves directly
+- **Alternatives considered**:
+  - Plain HTML: zero tooling but nav/footer must be duplicated in every file
+  - Hugo: fast but Go-based; less familiar template syntax
+  - Astro: more powerful but heavier; overkill for a content/lead-gen site
+- **Consequences**:
+  - Node.js + npm required in the build environment (not at runtime)
+  - Output: `_site/` directory of static HTML, CSS, JS, and assets
+  - Caddy should serve from `_site/`
+
 ## ADR-005 — No analytics or tracking in v1
 - **Status**: Accepted
 - **Context**: Stakeholder decided against tracking for simplicity.