diff --git a/.github/workflows/daily-multi-device-docs-tester.lock.yml b/.github/workflows/daily-multi-device-docs-tester.lock.yml
index f04eb38d515..abfddc9b1f6 100644
--- a/.github/workflows/daily-multi-device-docs-tester.lock.yml
+++ b/.github/workflows/daily-multi-device-docs-tester.lock.yml
@@ -1,4 +1,4 @@
-# gh-aw-metadata: {"schema_version":"v4","frontmatter_hash":"89fe6bb3bc7a452f74f731a5016ed268b63e44d322061a7dc884039f64c61dbc","body_hash":"09681b188b196d76d4a274d165483a7a327abca0f95bf4cf5cee6766dd608b27","strict":true,"agent_id":"pi","agent_model":"copilot/gpt-5.4","engine_versions":{"pi":"0.80.2"}}
+# gh-aw-metadata: {"schema_version":"v4","frontmatter_hash":"cabc740db4e2725e0e69c1710b0e73d488523b2065ff002b4899cb1491238afc","body_hash":"09681b188b196d76d4a274d165483a7a327abca0f95bf4cf5cee6766dd608b27","strict":true,"agent_id":"pi","agent_model":"copilot/gpt-5.4","engine_versions":{"pi":"0.80.2"}}
 # gh-aw-manifest: {"version":1,"secrets":["COPILOT_GITHUB_TOKEN","GH_AW_GITHUB_MCP_SERVER_TOKEN","GH_AW_GITHUB_TOKEN","GH_AW_OTEL_GRAFANA_AUTHORIZATION","GH_AW_OTEL_GRAFANA_ENDPOINT","GH_AW_OTEL_SENTRY_AUTHORIZATION","GH_AW_OTEL_SENTRY_ENDPOINT","GITHUB_TOKEN"],"actions":[{"repo":"actions/cache/restore","sha":"27d5ce7f107fe9357f9df03efb73ab90386fccae","version":"v5.0.5"},{"repo":"actions/cache/save","sha":"27d5ce7f107fe9357f9df03efb73ab90386fccae","version":"v5.0.5"},{"repo":"actions/checkout","sha":"9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0","version":"v7.0.0"},{"repo":"actions/download-artifact","sha":"3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c","version":"v8.0.1"},{"repo":"actions/github-script","sha":"3a2844b7e9c422d3c10d287c895573f7108da1b3","version":"v9.0.0"},{"repo":"actions/setup-node","sha":"48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e","version":"v6.4.0"},{"repo":"actions/upload-artifact","sha":"043fb46d1a93c77aae656e7c1c64a875d1fc6a0a","version":"v7.0.1"}],"containers":[{"image":"ghcr.io/github/gh-aw-firewall/agent:0.27.11","digest":"sha256:979723c628182da7729333f2208bb249fd25ddee579645cf9a3892d681a929c7","pinned_image":"ghcr.io/github/gh-aw-firewall/agent:0.27.11@sha256:979723c628182da7729333f2208bb249fd25ddee579645cf9a3892d681a929c7"},{"image":"ghcr.io/github/gh-aw-firewall/api-proxy:0.27.11","digest":"sha256:807e4831999b44513b0a66e5859d478dc4da7ae74ab1918cec967d513f95bf9d","pinned_image":"ghcr.io/github/gh-aw-firewall/api-proxy:0.27.11@sha256:807e4831999b44513b0a66e5859d478dc4da7ae74ab1918cec967d513f95bf9d"},{"image":"ghcr.io/github/gh-aw-firewall/cli-proxy:0.27.11"},{"image":"ghcr.io/github/gh-aw-firewall/squid:0.27.11","digest":"sha256:ff27ea0525ad953a6adee28a5fbe9d2e22be47dbec755c15767af4ea3f91df7d","pinned_image":"ghcr.io/github/gh-aw-firewall/squid:0.27.11@sha256:ff27ea0525ad953a6adee28a5fbe9d2e22be47dbec755c15767af4ea3f91df7d"},{"image":"ghcr.io/github/gh-aw-mcpg:v0.3.30","digest":"sha256:35625d1a2269b1238606078c879f59a91cffc4ac33eb54bf39c6418822c1a8be","pinned_image":"ghcr.io/github/gh-aw-mcpg:v0.3.30@sha256:35625d1a2269b1238606078c879f59a91cffc4ac33eb54bf39c6418822c1a8be"},{"image":"ghcr.io/github/gh-aw-node","digest":"sha256:529d02eb970b1161aa25c593a9c3df57fdfad5a8add328cb3b6eccef66f3183b","pinned_image":"ghcr.io/github/gh-aw-node@sha256:529d02eb970b1161aa25c593a9c3df57fdfad5a8add328cb3b6eccef66f3183b"},{"image":"ghcr.io/github/github-mcp-server:v1.4.0","digest":"sha256:2afb26356481d1a350e14544a6e160f7f7ec1561a1ea309b823665abf0309036","pinned_image":"ghcr.io/github/github-mcp-server:v1.4.0@sha256:2afb26356481d1a350e14544a6e160f7f7ec1561a1ea309b823665abf0309036"}]}
 # This file was automatically generated by gh-aw. DO NOT EDIT. To debug this workflow, load the skill at https://github.com/github/gh-aw/blob/main/debug.md
 #
@@ -559,6 +559,12 @@ jobs:
         run: |
           cd "$EXPR_GITHUB_WORKSPACE/docs"
           npm install
+      - env:
+          EXPR_GITHUB_WORKSPACE: ${{ github.workspace }}
+        name: Resolve slide deck PDF
+        run: |
+          cd "$EXPR_GITHUB_WORKSPACE/docs"
+          node ../scripts/ensure-docs-slide-pdf.js
       - env:
           EXPR_GITHUB_RUN_ID: ${{ github.run_id }}
           EXPR_GITHUB_WORKSPACE: ${{ github.workspace }}
diff --git a/.github/workflows/daily-multi-device-docs-tester.md b/.github/workflows/daily-multi-device-docs-tester.md
index 630576b3b79..7eab244f2ac 100644
--- a/.github/workflows/daily-multi-device-docs-tester.md
+++ b/.github/workflows/daily-multi-device-docs-tester.md
@@ -80,6 +80,12 @@ pre-agent-steps:
     run: |
       cd "$EXPR_GITHUB_WORKSPACE/docs"
       npm install
+  - name: Resolve slide deck PDF
+    env:
+      EXPR_GITHUB_WORKSPACE: ${{ github.workspace }}
+    run: |
+      cd "$EXPR_GITHUB_WORKSPACE/docs"
+      node ../scripts/ensure-docs-slide-pdf.js
   - name: Start docs server
     env:
       EXPR_GITHUB_RUN_ID: ${{ github.run_id }}
diff --git a/docs/package.json b/docs/package.json
index 0b190986a72..f34cae02c1d 100644
--- a/docs/package.json
+++ b/docs/package.json
@@ -7,6 +7,7 @@
   },
   "scripts": {
     "dev": "astro dev",
+    "predev": "npm run build:slides",
     "start": "astro dev",
     "prebuild": "npm run generate-agent-factory && npm run generate-model-tables && npm run build:slides",
     "build": "rm -rf dist && astro build",
diff --git a/docs/tests/mobile-responsive.spec.ts b/docs/tests/mobile-responsive.spec.ts
index a63ef1121a0..31aab7bdae0 100644
--- a/docs/tests/mobile-responsive.spec.ts
+++ b/docs/tests/mobile-responsive.spec.ts
@@ -199,4 +199,45 @@ test.describe('Mobile and Responsive Layout', () => {
 
     await context.close();
   });
+
+  // Verify mobile navigation toggle: hamburger menu nav links become visible on narrow viewports.
+  // Addresses the manual verification recommendation from the 2026-06-24 multi-device docs test report.
+  test('hamburger menu toggles navigation visibility on mobile viewport', async ({ browser }) => {
+    const context = await browser.newContext({
+      viewport: { width: 390, height: 844 },
+      javaScriptEnabled: true,
+    });
+    const page = await context.newPage();
+
+    await page.goto('/gh-aw/introduction/overview/');
+    await page.waitForLoadState('networkidle');
+
+    // The hamburger button must be present and focusable on a narrow mobile viewport.
+    const hamburgerBtn = page.locator('.hamburger-btn');
+    await expect(hamburgerBtn).toBeVisible();
+    await expect(hamburgerBtn).toHaveAttribute('aria-expanded', 'false');
+
+    // The dropdown must be hidden before the button is clicked.
+    const dropdown = page.locator('.tablet-dropdown');
+    await expect(dropdown).toBeHidden();
+
+    // Click the button; the dropdown must become visible and contain nav links.
+    await hamburgerBtn.click();
+    await expect(hamburgerBtn).toHaveAttribute('aria-expanded', 'true');
+    await expect(dropdown).toBeVisible();
+
+    const navLinks = dropdown.locator('.dropdown-link');
+    const linkCount = await navLinks.count();
+    expect(linkCount).toBeGreaterThan(0);
+    for (const link of await navLinks.all()) {
+      await expect(link).toBeVisible();
+    }
+
+    // A second click must close the dropdown.
+    await hamburgerBtn.click();
+    await expect(hamburgerBtn).toHaveAttribute('aria-expanded', 'false');
+    await expect(dropdown).toBeHidden();
+
+    await context.close();
+  });
 });
diff --git a/scripts/ensure-docs-slide-pdf.js b/scripts/ensure-docs-slide-pdf.js
index 7c0d32fa4a8..367bf6014de 100644
--- a/scripts/ensure-docs-slide-pdf.js
+++ b/scripts/ensure-docs-slide-pdf.js
@@ -49,6 +49,47 @@ function getGitRef() {
   }
 }
 
+/**
+ * Creates a minimal valid single-page PDF placeholder used when the real slide
+ * deck cannot be fetched (e.g. in sandboxed dev/test environments without LFS
+ * or media.githubusercontent.com access).  The placeholder carries the valid
+ * PDF header so pdfjs-dist can parse it without throwing InvalidPDFException.
+ */
+function createPlaceholderPdfBytes() {
+  const parts = [];
+  const offsets = [];
+
+  function write(str) {
+    parts.push(Buffer.from(str, "latin1"));
+  }
+
+  function currentOffset() {
+    return parts.reduce((sum, buf) => sum + buf.length, 0);
+  }
+
+  write("%PDF-1.4\n");
+
+  offsets[1] = currentOffset();
+  write("1 0 obj\n<</Type /Catalog /Pages 2 0 R>>\nendobj\n");
+
+  offsets[2] = currentOffset();
+  write("2 0 obj\n<</Type /Pages /Kids [3 0 R] /Count 1>>\nendobj\n");
+
+  offsets[3] = currentOffset();
+  write("3 0 obj\n<</Type /Page /Parent 2 0 R /MediaBox [0 0 612 792]>>\nendobj\n");
+
+  const xrefOffset = currentOffset();
+  write("xref\n0 4\n");
+  write("0000000000 65535 f \n");
+  write(offsets[1].toString().padStart(10, "0") + " 00000 n \n");
+  write(offsets[2].toString().padStart(10, "0") + " 00000 n \n");
+  write(offsets[3].toString().padStart(10, "0") + " 00000 n \n");
+  write("trailer\n<</Size 4 /Root 1 0 R>>\n");
+  write("startxref\n" + xrefOffset + "\n%%EOF\n");
+
+  return Buffer.concat(parts);
+}
+
 async function readPdfBytes() {
   const bytes = fs.readFileSync(SOURCE_PATH);
   if (isPdf(bytes)) {
@@ -65,17 +106,22 @@ async function readPdfBytes() {
 
   console.warn(`Detected Git LFS pointer at ${SOURCE_PATH}; downloading ${url}`);
 
-  const response = await fetch(url);
-  if (!response.ok) {
-    throw new Error(`Failed to download slide deck PDF: ${response.status} ${response.statusText}`);
-  }
+  try {
+    const response = await fetch(url);
+    if (!response.ok) {
+      throw new Error(`Failed to download slide deck PDF: ${response.status} ${response.statusText}`);
+    }
 
-  const downloadedBytes = Buffer.from(await response.arrayBuffer());
-  if (!isPdf(downloadedBytes)) {
-    throw new Error(`Downloaded slide deck from ${url} is not a real PDF.`);
-  }
+    const downloadedBytes = Buffer.from(await response.arrayBuffer());
+    if (!isPdf(downloadedBytes)) {
+      throw new Error(`Downloaded slide deck from ${url} is not a real PDF.`);
+    }
 
-  return downloadedBytes;
+    return downloadedBytes;
+  } catch (error) {
+    console.warn(`Warning: Could not download slide deck PDF (${error.message}). Using placeholder PDF.`);
+    return createPlaceholderPdfBytes();
+  }
 }
 
 async function main() {