diff --git a/src/pages/docs/_layout.tsx b/src/pages/docs/_layout.tsx
index c3e6c46..2a04329 100644
--- a/src/pages/docs/_layout.tsx
+++ b/src/pages/docs/_layout.tsx
@@ -108,7 +108,7 @@ export function DocsLayout({ children }: Props) {
 
   return (
     <SiteLayout variant="docs">
-      <Container size="xl" class="docs-channel">
+      <Container direction="column" size="xl" class="docs-channel">
         <SidebarScope class="docs-scope">
           <Sidebar class="docs-desktop-sidebar">
             <DocsNavigation />
diff --git a/src/pages/marketing/components.tsx b/src/pages/marketing/components.tsx
index 2672ffd..316bf40 100644
--- a/src/pages/marketing/components.tsx
+++ b/src/pages/marketing/components.tsx
@@ -12,7 +12,7 @@ type HeroProps = {
 export function EditorialHero({ title, lede }: HeroProps) {
   return (
     <section class="editorial-hero" aria-labelledby="editorial-title">
-      <Container size="xl">
+      <Container direction="column" size="xl">
         <h1 id="editorial-title">{title}</h1>
         <p class="editorial-hero__lede">{lede}</p>
       </Container>
diff --git a/src/pages/marketing/home.tsx b/src/pages/marketing/home.tsx
index 15141ff..af0be31 100644
--- a/src/pages/marketing/home.tsx
+++ b/src/pages/marketing/home.tsx
@@ -53,7 +53,7 @@ export function HomePage() {
       </section>
 
       <section class="differentiation" aria-labelledby="differentiation-title">
-        <Container class="differentiation__inner" size="xl">
+        <Container class="differentiation__inner" direction="column" size="xl">
           <div class="differentiation__heading">
             <h2 id="differentiation-title">This is the whole routing layer.</h2>
             <p>
diff --git a/src/pages/marketing/not-found.tsx b/src/pages/marketing/not-found.tsx
index 8c22e1e..3743572 100644
--- a/src/pages/marketing/not-found.tsx
+++ b/src/pages/marketing/not-found.tsx
@@ -5,7 +5,7 @@ import { Button, Container } from '@askrjs/themes/components';
 export function NotFoundPage() {
   return (
     <section class="not-found" aria-labelledby="not-found-title">
-      <Container class="not-found__inner" size="xl">
+      <Container class="not-found__inner" direction="column" size="xl">
         <span aria-hidden="true">404</span>
         <h1 id="not-found-title">This route does not exist.</h1>
         <p>
diff --git a/src/pages/site-footer.tsx b/src/pages/site-footer.tsx
index bb6e2fc..b567928 100644
--- a/src/pages/site-footer.tsx
+++ b/src/pages/site-footer.tsx
@@ -17,7 +17,7 @@ import { GitHubMark } from './site-header';
 export function SiteFooter() {
   return (
     <Footer class="site-footer">
-      <Container size="xl" paddingY="xl">
+      <Container direction="column" size="xl" paddingY="xl">
         <FooterContent class="marketing-footer__columns">
           <FooterSection>
             <FooterTitle>
diff --git a/src/pages/site-header.tsx b/src/pages/site-header.tsx
index 40e16ac..fbcd032 100644
--- a/src/pages/site-header.tsx
+++ b/src/pages/site-header.tsx
@@ -64,7 +64,7 @@ export function SiteThemeToggle() {
 export function SiteHeader() {
   return (
     <Header class="site-header" sticky>
-      <Container size="xl">
+      <Container direction="column" size="xl">
         <Navbar aria-label="Primary navigation">
           <NavBrand>
             <AskrBrand />
diff --git a/tests/browser/marketing-layout.test.tsx b/tests/browser/marketing-layout.test.tsx
new file mode 100644
index 0000000..e1aa741
--- /dev/null
+++ b/tests/browser/marketing-layout.test.tsx
@@ -0,0 +1,151 @@
+import { page, userEvent } from '@vitest/browser/context';
+import { cleanupApp, createSPA } from '@askrjs/askr/boot';
+import { createRouteRegistry } from '@askrjs/askr/router';
+import { afterEach, beforeEach, describe, expect, it } from 'vite-plus/test';
+import {
+  marketingRouteMetadata,
+  registerMarketingRoutes,
+} from '../../src/pages/marketing/_routes';
+import '../../src/styles.css';
+
+const registry = createRouteRegistry(() => registerMarketingRoutes());
+const routes = Object.keys(marketingRouteMetadata);
+const editorialRoutes = routes.filter(
+  (route) => route !== '/' && route !== '/404'
+);
+const viewports = [
+  { name: 'mobile', width: 390, height: 844 },
+  { name: 'desktop', width: 1440, height: 1000 },
+] as const;
+const themes = ['light', 'dark'] as const;
+
+async function settle(): Promise<void> {
+  await Promise.resolve();
+  await Promise.resolve();
+  await new Promise((resolve) => requestAnimationFrame(resolve));
+}
+
+function requiredElement<T extends HTMLElement>(
+  root: ParentNode,
+  selector: string
+): T {
+  const element = root.querySelector<T>(selector);
+  if (!element) throw new Error(`Missing expected element: ${selector}`);
+  return element;
+}
+
+function expectVerticalChildren(element: HTMLElement): void {
+  expect(getComputedStyle(element).display).toBe('flex');
+  expect(getComputedStyle(element).flexDirection).toBe('column');
+
+  const children = Array.from(element.children, (child) =>
+    child.getBoundingClientRect()
+  );
+  for (let index = 1; index < children.length; index += 1) {
+    expect(children[index]!.top).toBeGreaterThanOrEqual(
+      children[index - 1]!.bottom - 1
+    );
+  }
+}
+
+describe('marketing page layout', () => {
+  let container: HTMLDivElement | undefined;
+
+  beforeEach(() => {
+    localStorage.removeItem('askr-theme');
+    document.documentElement.removeAttribute('data-theme');
+    container = document.createElement('div');
+    document.body.appendChild(container);
+  });
+
+  afterEach(async () => {
+    if (container) {
+      cleanupApp(container);
+      container.remove();
+      container = undefined;
+    }
+    localStorage.removeItem('askr-theme');
+    document.documentElement.removeAttribute('data-theme');
+    await page.viewport(1280, 900);
+  });
+
+  for (const viewport of viewports) {
+    for (const theme of themes) {
+      for (const route of routes) {
+        it(`keeps ${route} intact at ${viewport.name} width in ${theme} mode`, async () => {
+          await page.viewport(viewport.width, viewport.height);
+          window.history.replaceState({}, '', route);
+          await createSPA({ root: container!, registry });
+          await settle();
+
+          if (theme === 'dark') {
+            const toggle = requiredElement<HTMLElement>(
+              container!,
+              '[data-theme-control="toggle"]'
+            );
+            await userEvent.click(toggle);
+            await settle();
+          }
+
+          expect(document.documentElement.dataset.theme).toBe(theme);
+
+          const shell = requiredElement<HTMLElement>(container!, '.site-shell');
+          expect(shell.scrollWidth).toBeLessThanOrEqual(shell.clientWidth + 1);
+
+          expect(
+            getComputedStyle(
+              requiredElement<HTMLElement>(
+                shell,
+                'header.site-header > [data-slot="container"]'
+              )
+            ).flexDirection
+          ).toBe('column');
+
+          const footerContainer = requiredElement<HTMLElement>(
+            shell,
+            'footer.site-footer > [data-slot="container"]'
+          );
+          expectVerticalChildren(footerContainer);
+
+          const footerColumns = requiredElement<HTMLElement>(
+            footerContainer,
+            '.marketing-footer__columns'
+          );
+          const footerColumnCount =
+            getComputedStyle(footerColumns).gridTemplateColumns.split(
+              ' '
+            ).length;
+          expect(footerColumnCount).toBe(viewport.name === 'mobile' ? 1 : 3);
+
+          if (route === '/') {
+            const differentiation = requiredElement<HTMLElement>(
+              shell,
+              '.differentiation__inner'
+            );
+            expectVerticalChildren(differentiation);
+
+            const body = requiredElement<HTMLElement>(
+              differentiation,
+              '.differentiation__body'
+            );
+            const bodyColumnCount =
+              getComputedStyle(body).gridTemplateColumns.split(' ').length;
+            expect(bodyColumnCount).toBe(viewport.name === 'mobile' ? 1 : 2);
+          } else if (route === '/404') {
+            expectVerticalChildren(
+              requiredElement<HTMLElement>(shell, '.not-found__inner')
+            );
+          } else {
+            expect(editorialRoutes).toContain(route);
+            expectVerticalChildren(
+              requiredElement<HTMLElement>(
+                shell,
+                '.editorial-hero > [data-slot="container"]'
+              )
+            );
+          }
+        });
+      }
+    }
+  }
+});