diff --git a/.github/workflows/verify-build.yml b/.github/workflows/verify-build.yml
new file mode 100644
index 0000000..03b4a52
--- /dev/null
+++ b/.github/workflows/verify-build.yml
@@ -0,0 +1,28 @@
+name: Verify build
+
+on:
+  pull_request:
+    branches: [main]
+  push:
+    branches: [main]
+
+permissions:
+  contents: read
+
+concurrency:
+  group: verify-build-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  verify:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: npm
+      - run: npm ci
+      - run: npm test
+      - run: npm run build
+      - run: npm run verify:build
diff --git a/docs/codebase-summary.md b/docs/codebase-summary.md
index 3a1ac49..9f562bc 100644
--- a/docs/codebase-summary.md
+++ b/docs/codebase-summary.md
@@ -46,7 +46,9 @@
 |------|---------|
 | `svelte.config.js` | adapter-static (HTML export), dual basePath via BUILD_PROFILE env, SvelteKit PWA plugin config. |
 | `vite.config.js` | Tailwind + SvelteKit + PWA plugins. codeserver HMR config (port, allowedHosts, hmr). |
-| `package.json` | SvelteKit 2, Svelte 5 (runes), Tailwind 4, Vite, @vite-pwa/sveltekit. Scripts: dev, dev:codeserver, build, build:gh, lint, test, test:watch. |
+| `package.json` | SvelteKit 2, Svelte 5 (runes), Tailwind 4, Vite, @vite-pwa/sveltekit. Scripts: dev, dev:codeserver, build, build:gh, lint, test, test:watch, verify:build. |
+| `scripts/verify-build-inline-scripts.mjs` | Post-build CSP guard. Counts inline `<script>` tags in `build/index.html` and fails if > EXPECTED_INLINE (1). Catches future SvelteKit upgrades that add inline blocks the CSP `'unsafe-inline'` relaxation isn't calibrated for. |
+| `.github/workflows/verify-build.yml` | CI: on push/PR to main runs `npm test && npm run build && npm run verify:build` to enforce the inline-script guard above. |
 | `eslint.config.mjs` | ESLint 9 flat config (@eslint/js + eslint-plugin-svelte). Declares Svelte 5 rune globals. |
 | `jsconfig.json` | Path alias `$lib`, no checkJs. |
 | `.gitignore` | Excludes node_modules, build, .env.local, etc. |
diff --git a/package.json b/package.json
index cdf5bbc..34968e1 100644
--- a/package.json
+++ b/package.json
@@ -11,7 +11,8 @@
     "preview": "vite preview",
     "lint": "eslint .",
     "test": "vitest run",
-    "test:watch": "vitest"
+    "test:watch": "vitest",
+    "verify:build": "node scripts/verify-build-inline-scripts.mjs"
   },
   "optionalDependencies": {
     "lightningcss-linux-x64-gnu": "1.32.0"
diff --git a/plans/260428-0927-implement-todo-backlog/phase-02-ci-inline-script-guard.md b/plans/260428-0927-implement-todo-backlog/phase-02-ci-inline-script-guard.md
index 41a6ad2..a3c4a03 100644
--- a/plans/260428-0927-implement-todo-backlog/phase-02-ci-inline-script-guard.md
+++ b/plans/260428-0927-implement-todo-backlog/phase-02-ci-inline-script-guard.md
@@ -1,9 +1,10 @@
 ---
 name: CI inline-script guard
 phase: 2
-status: todo
+status: completed
 priority: high
 effort: 30m
+completed: 2026-04-28
 ---
 
 # Phase 2 — CI inline-script guard
diff --git a/plans/260428-0927-implement-todo-backlog/plan.md b/plans/260428-0927-implement-todo-backlog/plan.md
index e0a69f5..3c4e4f2 100644
--- a/plans/260428-0927-implement-todo-backlog/plan.md
+++ b/plans/260428-0927-implement-todo-backlog/plan.md
@@ -18,7 +18,7 @@ YAGNI — parking-lot features and upstream-blocked items skipped.
 | # | Phase | File |
 |---|-------|------|
 | 1 | Auto-tick integration test ✅ | `phase-01-auto-tick-test.md` |
-| 2 | CI inline-script guard | `phase-02-ci-inline-script-guard.md` |
+| 2 | CI inline-script guard ✅ | `phase-02-ci-inline-script-guard.md` |
 | 3 | Mode picker glyph redesign | `phase-03-mode-picker-glyphs.md` |
 | 4 | Settings modal sticky on small screens | `phase-04-settings-modal-sticky.md` |
 | 5 | Per-row "Chờ" indicator | `phase-05-cho-row-indicator.md` |
diff --git a/scripts/verify-build-inline-scripts.mjs b/scripts/verify-build-inline-scripts.mjs
new file mode 100644
index 0000000..ceec357
--- /dev/null
+++ b/scripts/verify-build-inline-scripts.mjs
@@ -0,0 +1,43 @@
+#!/usr/bin/env node
+/**
+ * Guard: count inline <script> tags in build/index.html. SvelteKit
+ * currently emits exactly one inline bootstrap block — the relaxation
+ * we ship in static/_headers (`script-src 'self' 'unsafe-inline'`)
+ * is calibrated to that. If a future SvelteKit upgrade adds another
+ * inline block, this guard fails CI so we either (a) hash the new
+ * block into CSP or (b) bump EXPECTED_INLINE intentionally.
+ *
+ * Inline = no `src=` attribute. Module/external scripts are excluded.
+ */
+import { readFileSync } from "node:fs";
+
+const EXPECTED_INLINE = 1;
+const HTML_PATH = "build/index.html";
+
+let html;
+try {
+  html = readFileSync(HTML_PATH, "utf8");
+} catch (e) {
+  console.error(`verify-build: cannot read ${HTML_PATH} — run \`npm run build\` first.`);
+  process.exit(2);
+}
+
+const inline = (html.match(/<script(?![^>]*\bsrc=)[^>]*>/g) || []).length;
+
+if (inline > EXPECTED_INLINE) {
+  console.error(
+    `verify-build: found ${inline} inline <script> tags in ${HTML_PATH} (expected ${EXPECTED_INLINE}).\n` +
+      `If this is intentional, update EXPECTED_INLINE in scripts/verify-build-inline-scripts.mjs\n` +
+      `AND add the SHA-256 hash(es) of the new inline block(s) to static/_headers script-src.`,
+  );
+  process.exit(1);
+}
+
+if (inline < EXPECTED_INLINE) {
+  console.warn(
+    `verify-build: found ${inline} inline <script> tags but expected ${EXPECTED_INLINE}.\n` +
+      `If SvelteKit changed its bootstrap strategy, lower EXPECTED_INLINE and tighten CSP.`,
+  );
+}
+
+console.log(`verify-build: ${inline} inline <script> tag(s) — OK.`);