diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e03d4a5..ac1f7a3 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -77,6 +77,39 @@ jobs:
         env:
           CHROMATIC_ARCHIVE_LOCATION: ./test-results
 
+  lighthouse:
+    name: Lighthouse CI
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up pnpm
+        uses: pnpm/action-setup@v4
+
+      - name: Set up Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: 22
+          cache: pnpm
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      - name: Build
+        run: pnpm build
+
+      # Tests the static dist/ output directly, so /api/geo and the Vercel
+      # Analytics script (both Vercel-runtime-only) 404 here even though
+      # they work in production — accounted for in lighthouserc.json's
+      # best-practices threshold.
+      - name: Run Lighthouse CI
+        uses: treosh/lighthouse-ci-action@v11
+        with:
+          configPath: ./lighthouserc.json
+          uploadArtifacts: true
+          temporaryPublicStorage: true
+
   lint:
     name: Lint + format
     runs-on: ubuntu-latest
diff --git a/.gitignore b/.gitignore
index 43a37a6..ed49f68 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,6 +3,8 @@ dist/
 # playwright output
 test-results/
 playwright-report/
+# lighthouse ci output
+.lighthouseci/
 # generated types
 .astro/
 
diff --git a/README.md b/README.md
index f4da86a..4a08657 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,10 @@
 # youthphase.dev
 
+![Lighthouse Performance](https://img.shields.io/badge/Lighthouse%20Performance-100-brightgreen)
+![Lighthouse Accessibility](https://img.shields.io/badge/Lighthouse%20Accessibility-100-brightgreen)
+![Lighthouse Best Practices](https://img.shields.io/badge/Lighthouse%20Best%20Practices-100-brightgreen)
+![Lighthouse SEO](https://img.shields.io/badge/Lighthouse%20SEO-100-brightgreen)
+
 Personal site of Amy Lam. Built with [Astro](https://astro.build) and
 [Tailwind CSS](https://tailwindcss.com), package-managed with
 [pnpm](https://pnpm.io), linted with Prettier/ESLint/Stylelint. This
@@ -117,6 +122,17 @@ Key files:
 every sun altitude and fails if any ink/background pairing drops below
 WCAG AAA — see [the sky section](#the-sky) above.
 
+[Lighthouse CI](https://github.com/GoogleChrome/lighthouse-ci) runs
+against every page in the built `dist/` output and fails the build if
+Performance drops below 90, Best Practices drops below 95, or
+Accessibility or SEO drop below 100 — thresholds set in
+[lighthouserc.json](lighthouserc.json). Performance gets a lower floor
+because build-to-build timing variance on CI runners is real; Best
+Practices gets one because testing the static `dist/` directly (rather
+than a deployed Vercel environment) makes `/api/geo` and the Vercel
+Analytics script 404, which they don't in production. The badges above
+reflect an actual production run, which hits neither issue.
+
 The same Playwright run also feeds [Chromatic](https://www.chromatic.com)
 visual regression testing via
 [`@chromatic-com/playwright`](https://www.chromatic.com/docs/playwright/) —
@@ -148,8 +164,8 @@ to actually publish.
 
 [GitHub Actions](https://github.com/features/actions)
 (`.github/workflows/ci.yml`) runs the build, `check:contrast`, the full
-Playwright suite, and all three linters on every push to `main` and on
-every pull request.
+Playwright suite, Lighthouse CI, and all three linters on every push to
+`main` and on every pull request.
 
 ## Deploying (Vercel)
 
diff --git a/lighthouserc.json b/lighthouserc.json
new file mode 100644
index 0000000..e70c96a
--- /dev/null
+++ b/lighthouserc.json
@@ -0,0 +1,19 @@
+{
+  "ci": {
+    "collect": {
+      "staticDistDir": "./dist",
+      "numberOfRuns": 3
+    },
+    "assert": {
+      "assertions": {
+        "categories:performance": ["error", { "minScore": 0.9 }],
+        "categories:accessibility": ["error", { "minScore": 1 }],
+        "categories:best-practices": ["error", { "minScore": 0.95 }],
+        "categories:seo": ["error", { "minScore": 1 }]
+      }
+    },
+    "upload": {
+      "target": "temporary-public-storage"
+    }
+  }
+}
diff --git a/src/layouts/Layout.astro b/src/layouts/Layout.astro
index 25f8a29..71e32bc 100644
--- a/src/layouts/Layout.astro
+++ b/src/layouts/Layout.astro
@@ -43,6 +43,7 @@ const ogImage = new URL('/og.png', Astro.site);
     <div
       id="glow"
       aria-hidden="true"
+      data-chromatic="ignore"
       class="pointer-events-none fixed size-[60vw] -translate-1/2 rounded-full opacity-0 blur-[55px] sm:size-[45vmin] sm:blur-[90px]"
     >
     </div>
@@ -59,6 +60,7 @@ const ogImage = new URL('/og.png', Astro.site);
     <div
       id="moon-core"
       aria-hidden="true"
+      data-chromatic="ignore"
       class="pointer-events-none fixed size-[7px] -translate-1/2 rounded-full opacity-0"
     >
     </div>
@@ -73,7 +75,12 @@ const ogImage = new URL('/og.png', Astro.site);
          sliding off another circle. sky.ts positions it with the moon and
          rewrites the shadow path each tick; visibility and the bloom
          transition live in global.css under html.moon-cycle. -->
-    <div id="moon-face" aria-hidden="true" class="pointer-events-none fixed size-14 -translate-1/2">
+    <div
+      id="moon-face"
+      aria-hidden="true"
+      data-chromatic="ignore"
+      class="pointer-events-none fixed size-14 -translate-1/2"
+    >
       <svg viewBox="0 0 100 100" class="size-full">
         <defs>
           <radialGradient id="moon-sphere" cx="42%" cy="38%" r="72%">
@@ -111,18 +118,29 @@ const ogImage = new URL('/og.png', Astro.site);
          moonlight rises softly from the stage and recedes (sky.ts).
          Sits below the page content in DOM order so the flood stays
          behind the text. -->
-    <div id="moon-finale" aria-hidden="true" class="pointer-events-none fixed inset-0 opacity-0">
+    <div
+      id="moon-finale"
+      aria-hidden="true"
+      data-chromatic="ignore"
+      class="pointer-events-none fixed inset-0 opacity-0"
+    >
     </div>
 
     <!-- Day-show shower cloud: a faint gray dim over the sky while the
          rain falls, lifting when the rainbow arrives (sky.ts). -->
-    <div id="cloud-dim" aria-hidden="true" class="pointer-events-none fixed inset-0 opacity-0">
+    <div
+      id="cloud-dim"
+      aria-hidden="true"
+      data-chromatic="ignore"
+      class="pointer-events-none fixed inset-0 opacity-0"
+    >
     </div>
 
     <!-- Day-show rainbow: the left leg of a bow whose arch is far off
          the upper right — mostly horizontal across the page, sweeping
          up as it exits (sky.ts triggers it; geometry in global.css). -->
-    <div id="rainbow" aria-hidden="true" class="pointer-events-none fixed"></div>
+    <div id="rainbow" aria-hidden="true" data-chromatic="ignore" class="pointer-events-none fixed">
+    </div>
 
     <!-- The easter egg's trigger is a triple-tap anywhere on the sky
          (sky.ts) — no dedicated touch target needed, so nothing ever
@@ -132,13 +150,20 @@ const ogImage = new URL('/og.png', Astro.site);
 
     <!-- The real night sky: sky.ts positions the brightest stars for the
          visitor's location and time. -->
-    <div id="stars" aria-hidden="true" class="pointer-events-none fixed inset-0 opacity-0"></div>
+    <div
+      id="stars"
+      aria-hidden="true"
+      data-chromatic="ignore"
+      class="pointer-events-none fixed inset-0 opacity-0"
+    >
+    </div>
 
     <!-- Contrast scrim: sky.ts raises its opacity when the gradient behind
          the center content can't meet AAA on its own (golden hour). -->
     <div
       id="scrim"
       aria-hidden="true"
+      data-chromatic="ignore"
       class="pointer-events-none fixed top-[48%] left-1/2 h-[44vh] w-[min(96vw,64rem)] -translate-1/2 rounded-[50%] opacity-0 blur-3xl"
     >
     </div>