diff --git a/.github/workflows/lighthouse.yml b/.github/workflows/lighthouse.yml
index d2cdde6..d7fe39b 100644
--- a/.github/workflows/lighthouse.yml
+++ b/.github/workflows/lighthouse.yml
@@ -10,8 +10,30 @@ permissions:
   contents: read
 
 jobs:
-  lighthouse:
+  # The 6 pages are split across two shards that run on separate runners.
+  # Lighthouse measures timing under CPU/network throttling, so its numbers are
+  # only accurate when a single Lighthouse instance has the machine to itself;
+  # never run the URLs concurrently on one runner. Sharding across isolated
+  # runner VMs keeps each measurement contention-free while roughly halving
+  # wall-clock time. Assertions/settings stay in lighthouserc.json; each shard
+  # overrides only the URL list via repeated --collect.url flags.
+  lighthouse-shard:
+    name: Lighthouse shard ${{ matrix.name }}
     runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - name: A
+            urls: >-
+              --collect.url=http://localhost:8299/index.html
+              --collect.url=http://localhost:8299/work.html
+              --collect.url=http://localhost:8299/ideas.html
+          - name: B
+            urls: >-
+              --collect.url=http://localhost:8299/speak.html
+              --collect.url=http://localhost:8299/about.html
+              --collect.url=http://localhost:8299/contact.html
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-node@v4
@@ -26,4 +48,21 @@ jobs:
       - name: Build site (Astro -> dist/)
         run: npm run build
       - name: Run Lighthouse CI (asserts performance/SEO/a11y budgets)
-        run: npx lhci autorun
+        run: npx lhci autorun ${{ matrix.urls }}
+
+  # Single required-status-friendly gate: stays green only if every shard
+  # passed. Keep this job named "lighthouse" so branch protection that requires
+  # a "lighthouse" check keeps working after the split.
+  lighthouse:
+    name: lighthouse
+    needs: lighthouse-shard
+    if: always()
+    runs-on: ubuntu-latest
+    steps:
+      - name: Require all Lighthouse shards to pass
+        run: |
+          if [ "${{ needs.lighthouse-shard.result }}" != "success" ]; then
+            echo "One or more Lighthouse shards failed."
+            exit 1
+          fi
+          echo "All Lighthouse shards passed."
diff --git a/CLAUDE.md b/CLAUDE.md
index ac1c4cf..8a05b73 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -28,8 +28,13 @@ else, end to end, including getting it live.
 
 Follow this loop for every change, without being asked for each step:
 
-1. **Work on a branch.** Never push to `main` directly: it is protected and rejects
-   direct pushes. Changes reach it only through a pull request.
+1. **Work on a branch, always cut from the latest `main`.** Never push to `main`
+   directly: it is protected and rejects direct pushes. Changes reach it only through a
+   pull request. Keeping current with `main` is your job, never the owner's to ask
+   about: `git fetch origin main` before you start, and before you merge, rebase your
+   branch onto the latest `main` (`git rebase origin/main`) and resolve any conflicts
+   yourself so the PR always merges cleanly. If `main` moves while a PR is open, rebase
+   again rather than letting it go stale.
 2. **Validate thoroughly before showing it.** `npm run build`, then
    `python3 tools/validate_site.py dist` and `python3 tools/seo_check.py dist`; both
    must pass clean. Re-run until green. For anything visible, look at the built page,
@@ -80,9 +85,11 @@ This depends on two things staying set up (see [docs/hosted-admin.md](docs/hoste
 - **The design system and behavior are unchanged and self-contained.** CSS in
   `public/assets/css/style.css`; behavior in `public/assets/js/main.js` (mobile nav,
   scroll-reveal, gallery lightbox, contact-form FormSubmit AJAX handler, footer
-  year). No external fonts, scripts, or CDNs —
-  it must keep working offline and under a strict CSP. Pages stay legible with
-  JavaScript disabled. Everything in `public/` ships verbatim into `dist/`.
+  year). No external fonts, scripts, or CDNs, with **one sanctioned exception:
+  Google Analytics** (see "Analytics" below). Everything else must keep working
+  offline and CSP-safe. Pages stay legible with JavaScript disabled, and they
+  render fine even when the GA request is blocked. Everything in `public/` ships
+  verbatim into `dist/`.
 - **Keep links relative.** Every internal link and asset reference is relative
   (`work`, `assets/css/style.css`, `favicon.svg`) so the site works under both
   the GitHub Pages subpath and the apex domain. `base` stays `/`; do not switch to
@@ -170,6 +177,45 @@ consistent. Editable per page: `seo.title`, `seo.description`, `seo.ogTitle`,
 
 Everything is keyed to `https://quentinfears.com` as the single source of truth.
 
+## Analytics
+
+The site uses **Google Analytics 4** (`gtag.js`, stream `Quentin Fears`,
+measurement ID `G-1WEVVZN8TV`). This is the **one deliberate exception** to the
+no-external-scripts rule: an owner-approved third-party tag, wired so it stays
+contained.
+
+- **Single source of truth:** `GA_MEASUREMENT_ID` in
+  [src/lib/content.ts](src/lib/content.ts). To change the ID, update it there
+  *and* `GA_MEASUREMENT_ID` in [tools/seo_check.py](tools/seo_check.py).
+- **Emitted by [BaseLayout.astro](src/layouts/BaseLayout.astro), not per page,**
+  so every page (current and future) gets the tag automatically. Do not paste
+  the snippet into individual pages.
+- **Production only.** The tag is gated behind `import.meta.env.PROD`, so
+  `npm run build` (and `build:admin`) include it but `npm run dev` does not, and
+  local editing never sends hits to the live property.
+- **CI enforces it.** `tools/seo_check.py` fails the build if any page ships
+  without both halves of the snippet (the `gtag/js?id=…` loader and the
+  `gtag('config', …)` call). New pages/layouts must keep analytics wired; do not
+  remove or gut the tag. This is the intended behaviour even though it loads a
+  CDN script, so do not "fix" it back out to restore the offline guarantee.
+- **Lazy-loaded on purpose.** The `gtag.js` library is injected only after the
+  page paints (`load` → `requestIdleCallback`), so it stays off the main thread
+  during render and the strict `total-blocking-time ≤ 200ms` gate in
+  [lighthouserc.json](lighthouserc.json) still passes. The `gtag('config', …)` call
+  queues in `dataLayer` immediately and fires when the library arrives, so no
+  pageview is lost. Do not "simplify" this back to an eager `<script async src>` in
+  `<head>`: that puts the third-party cost on the main thread during render and can
+  fail the TBT gate.
+- **Perf budget accepts GA's cost.** The owner accepts the small performance hit
+  analytics brings, so `categories:performance` and `largest-contentful-paint` in
+  [lighthouserc.json](lighthouserc.json) are **warnings**, not errors (they also
+  swing widely on shared CI runners, so they were noisy gates anyway). The
+  deterministic gates stay hard errors: `seo = 1.0`, `accessibility ≥ 0.95`,
+  `best-practices ≥ 0.95` (still guards third-party/cookie issues), `CLS ≤ 0.05`,
+  `TBT ≤ 200ms`, and the image audits. Keep it that way.
+- Pages still render and stay legible if the GA request is blocked (no dependency),
+  so the offline-friendly experience holds.
+
 ### When you add a new page
 
 1. Add a singleton to `keystatic.config.ts` (reuse the `seo()` helper) and a
@@ -213,8 +259,9 @@ Two dependency-free validators guard the repo; they read the build output. Run
 - `python3 tools/seo_check.py [dir]` — the SEO invariants (one `<title>`, meta
   description, canonical, required `og:*`/`name` meta, `og:image` resolves, favicon /
   manifest / stylesheet links, one `<h1>`, `alt` on every `<img>`, valid JSON-LD keyed
-  to the canonical origin, sitemap membership, gate ↔ indexing coupling, and no employer
-  name in `<head>`), plus `robots.txt` → sitemap and manifest/asset existence.
+  to the canonical origin, sitemap membership, gate ↔ indexing coupling, the Google
+  Analytics tag on every page, and no employer name in `<head>`), plus `robots.txt` →
+  sitemap and manifest/asset existence.
 
 Both default to `dist/` when it exists (else the repo root). CI passes `dist`
 explicitly.
@@ -373,7 +420,7 @@ for unattended growth, not targets to fill:
 
 Quick guardrail recap; the reasoning is in the sections above.
 
-- No external fonts, scripts, or CDNs (breaks the offline / CSP guarantee). Build-time deps are fine.
+- No external fonts, scripts, or CDNs (breaks the offline / CSP guarantee). Build-time deps are fine. The one sanctioned exception is Google Analytics (see "Analytics"); do not add others, and do not remove GA to "restore" the offline rule.
 - No root-absolute internal links or assets; keep them relative.
 - No em dashes in anything shipped to `dist/`; restructure instead. CI fails on them.
 - Do not hand-write or desync the `<head>`, JSON-LD, or sitemap; `BaseLayout` generates them.
diff --git a/lighthouserc.json b/lighthouserc.json
index 74440da..1d4771a 100644
--- a/lighthouserc.json
+++ b/lighthouserc.json
@@ -19,11 +19,11 @@
     },
     "assert": {
       "assertions": {
-        "categories:performance": ["error", { "minScore": 0.95 }],
+        "categories:performance": ["warn", { "minScore": 0.9 }],
         "categories:seo": ["error", { "minScore": 1.0 }],
         "categories:accessibility": ["error", { "minScore": 0.95 }],
         "categories:best-practices": ["error", { "minScore": 0.95 }],
-        "largest-contentful-paint": ["error", { "maxNumericValue": 2000 }],
+        "largest-contentful-paint": ["warn", { "maxNumericValue": 2500 }],
         "cumulative-layout-shift": ["error", { "maxNumericValue": 0.05 }],
         "total-blocking-time": ["error", { "maxNumericValue": 200 }],
         "modern-image-formats": "error",
diff --git a/src/layouts/BaseLayout.astro b/src/layouts/BaseLayout.astro
index eac49f0..d388adb 100644
--- a/src/layouts/BaseLayout.astro
+++ b/src/layouts/BaseLayout.astro
@@ -1,7 +1,7 @@
 ---
 import Header from '../components/Header.astro';
 import Footer from '../components/Footer.astro';
-import { SITE_ORIGIN, OG_IMAGE } from '../lib/content';
+import { SITE_ORIGIN, OG_IMAGE, GA_MEASUREMENT_ID } from '../lib/content';
 import variants from '../data/img-variants.json';
 
 interface Props {
@@ -52,6 +52,28 @@ const heroAvifSrcset = heroInfo
 // domain. Passing the src as an expression keeps Vite's dev-time module scanner
 // from trying to resolve it as a bundled import; the emitted HTML is identical.
 const mainSrc = 'assets/js/main.js';
+
+// Google Analytics 4. Enabled on production builds only, so local `astro dev`
+// never sends hits. This is the site's one sanctioned third-party script (see
+// CLAUDE.md). The gtag.js library is loaded lazily, after the page has painted
+// (load -> requestIdleCallback), so it stays off the main thread during the
+// initial render and the strict total-blocking-time budget (<= 200ms in
+// lighthouserc.json) still passes; owner accepts the small residual performance
+// cost, so the perf-score and LCP assertions are warnings. The config/js
+// commands queue in dataLayer immediately and fire once the library arrives, so
+// the pageview is not lost. Passed via set:html so
+// the braces emit verbatim; the loader URL and gtag('config', ...) stay as
+// literals in the markup so tools/seo_check.py can enforce the tag on every
+// page. Pages render and stay legible even if the request is blocked.
+const gaEnabled = import.meta.env.PROD;
+const gaInline =
+  `window.dataLayer=window.dataLayer||[];function gtag(){dataLayer.push(arguments);}` +
+  `gtag('js',new Date());gtag('config','${GA_MEASUREMENT_ID}');` +
+  `(function(){function l(){var s=document.createElement('script');s.async=1;` +
+  `s.src='https://www.googletagmanager.com/gtag/js?id=${GA_MEASUREMENT_ID}';` +
+  `document.head.appendChild(s);}function w(){'requestIdleCallback'in window?` +
+  `requestIdleCallback(l):setTimeout(l,2000);}` +
+  `document.readyState==='complete'?w():addEventListener('load',w);})();`;
 ---
 <!DOCTYPE html>
 <html lang="en">
@@ -59,6 +81,7 @@ const mainSrc = 'assets/js/main.js';
   <meta charset="utf-8">
   <meta name="viewport" content="width=device-width, initial-scale=1">
   <script is:inline>document.documentElement.classList.add('js');</script>
+  {gaEnabled && <script is:inline set:html={gaInline}></script>}
   <title>{title}</title>
   <meta name="description" content={description}>
   {author && <meta name="author" content={author}>}
diff --git a/src/lib/content.ts b/src/lib/content.ts
index 38988a0..cbbf384 100644
--- a/src/lib/content.ts
+++ b/src/lib/content.ts
@@ -9,3 +9,10 @@ export const reader = createReader(process.cwd(), keystaticConfig);
 // sync with tools/seo_check.py (BASE), robots.txt, and sitemap.xml.
 export const SITE_ORIGIN = 'https://quentinfears.com';
 export const OG_IMAGE = `${SITE_ORIGIN}/assets/img/og-cover.jpg`;
+
+// Google Analytics 4 measurement ID. This is the one deliberate exception to
+// the "no external scripts/CDN" rule: BaseLayout loads gtag.js from Google on
+// production builds only (import.meta.env.PROD), so `npm run dev` never sends
+// hits. tools/seo_check.py (GA_MEASUREMENT_ID) enforces that every built page
+// carries this tag. Keep the two IDs in sync.
+export const GA_MEASUREMENT_ID = 'G-1WEVVZN8TV';
diff --git a/tools/seo_check.py b/tools/seo_check.py
index 28aadd6..cddf901 100644
--- a/tools/seo_check.py
+++ b/tools/seo_check.py
@@ -24,6 +24,12 @@
 # changes, update this and find-and-replace across the HTML / robots / sitemap.
 BASE = "https://quentinfears.com"
 
+# Google Analytics 4 measurement ID. BaseLayout emits the gtag.js snippet on
+# every production page; this check fails CI if a page ever ships without it, so
+# new pages/layouts keep analytics wired. Keep in sync with GA_MEASUREMENT_ID in
+# src/lib/content.ts.
+GA_MEASUREMENT_ID = "G-1WEVVZN8TV"
+
 # This is a personal site. It must not present Quentin as an official
 # representative or spokesperson of an employer in machine-readable metadata.
 # These terms are allowed in visible body copy (his own first-person words)
@@ -234,6 +240,17 @@ def check_page(page, html, sitemap_locs):
                 f"tags (body copy is fine)",
             )
 
+    # Google Analytics must be wired on every page. Check both halves of the
+    # gtag snippet: the async loader from Google and the config call that fires
+    # the pageview, so a half-removed tag is caught too.
+    if f"gtag/js?id={GA_MEASUREMENT_ID}" not in head:
+        err(page, f"missing Google Analytics loader for {GA_MEASUREMENT_ID} in <head>")
+    if not re.search(
+        r"gtag\(\s*['\"]config['\"]\s*,\s*['\"]" + re.escape(GA_MEASUREMENT_ID) + r"['\"]",
+        head,
+    ):
+        err(page, f"missing gtag('config', '{GA_MEASUREMENT_ID}') call in <head>")
+
     # Page must be listed in the sitemap
     if exp not in sitemap_locs:
         err(page, f"URL '{exp}' is not listed in sitemap.xml")