diff --git a/src/hooks.server.ts b/src/hooks.server.ts
index 6049c45..81a181e 100644
--- a/src/hooks.server.ts
+++ b/src/hooks.server.ts
@@ -1,4 +1,6 @@
 import { getTranslationBundleBySlug } from '$lib/cms';
+import { isCmsAvailable } from '$lib/cms-health.server';
+import { maintenanceResponse } from '$lib/maintenance.server';
 import { TRANSLATION_BUNDLE_SLUG } from '$lib/constants';
 import type { Handle } from '@sveltejs/kit';
 
@@ -9,6 +11,8 @@ import type { Handle } from '@sveltejs/kit';
 const PAGE_CACHE_CONTROL =
   'public, max-age=0, s-maxage=30, stale-while-revalidate=300';
 
+const ASSET_EXT_RE = /\.(ico|png|jpe?g|webp|gif|svg|css|js|mjs|map|woff2?|ttf|otf|txt|xml|json|pdf)$/i;
+
 function isCacheablePath(pathname: string): boolean {
   if (pathname.startsWith('/api/')) return false;
   if (pathname.startsWith('/cms-images/')) return false;
@@ -16,7 +20,37 @@ function isCacheablePath(pathname: string): boolean {
   return true;
 }
 
+/** Pfade auf denen wir vor dem Resolve einen CMS-Health-Check machen. */
+function shouldHealthCheck(pathname: string): boolean {
+  if (pathname.startsWith('/api/')) return false;
+  if (pathname.startsWith('/_app/')) return false;
+  if (pathname.startsWith('/cms-images/')) return false;
+  if (pathname.startsWith('/cms-files/')) return false;
+  if (pathname === '/sitemap.xml' || pathname === '/robots.txt') return false;
+  if (ASSET_EXT_RE.test(pathname)) return false;
+  return true;
+}
+
+function isMaintenanceSimulation(pathname: string, search: URLSearchParams): boolean {
+  if (pathname === '/maintenance' || pathname === '/maintenance/') return true;
+  if (search.has('cms_down')) return true;
+  return false;
+}
+
 export const handle: Handle = async ({ event, resolve }) => {
+  // Simulation: erlaubt manuelles Triggern der Maintenance-Seite ohne
+  // CMS abzuschalten. /maintenance oder ?cms_down=1.
+  if (isMaintenanceSimulation(event.url.pathname, event.url.searchParams)) {
+    return maintenanceResponse(200);
+  }
+
+  // Echter Ausfall: vor dem ersten CMS-Call prüfen ob die API antwortet.
+  // Cached, daher kein Roundtrip pro Request.
+  if (event.request.method === 'GET' && shouldHealthCheck(event.url.pathname)) {
+    const ok = await isCmsAvailable();
+    if (!ok) return maintenanceResponse(503);
+  }
+
   try {
     const bundle = await getTranslationBundleBySlug(TRANSLATION_BUNDLE_SLUG, { locale: 'de' });
     if (bundle?.strings && typeof bundle.strings === 'object') {
diff --git a/src/lib/cms-health.server.ts b/src/lib/cms-health.server.ts
new file mode 100644
index 0000000..c069b46
--- /dev/null
+++ b/src/lib/cms-health.server.ts
@@ -0,0 +1,60 @@
+/**
+ * Health-Probe für die RustyCMS API. Ergebnisse werden kurz gecacht, damit nicht
+ * jeder Request einen extra Roundtrip auslöst. Bei Negativ-Status kürzere TTL,
+ * damit das Frontend zügig wieder hochkommt sobald das CMS antwortet.
+ */
+import { env } from '$env/dynamic/public';
+
+const HEALTHY_TTL_MS = 10_000;
+const UNHEALTHY_TTL_MS = 3_000;
+const PROBE_TIMEOUT_MS = 1_500;
+
+type CacheEntry = { healthy: boolean; expires: number };
+let cached: CacheEntry | null = null;
+let inflight: Promise<boolean> | null = null;
+
+function getBaseUrl(): string {
+  const url = env.PUBLIC_CMS_URL || 'http://localhost:3000';
+  return url.replace(/\/$/, '');
+}
+
+async function probe(): Promise<boolean> {
+  const base = getBaseUrl();
+  const ctrl = new AbortController();
+  const timer = setTimeout(() => ctrl.abort(), PROBE_TIMEOUT_MS);
+  try {
+    const res = await fetch(`${base}/api-docs/openapi.json`, {
+      method: 'GET',
+      signal: ctrl.signal,
+    });
+    return res.ok;
+  } catch {
+    return false;
+  } finally {
+    clearTimeout(timer);
+  }
+}
+
+export async function isCmsAvailable(): Promise<boolean> {
+  const now = Date.now();
+  if (cached && cached.expires > now) return cached.healthy;
+  if (inflight) return inflight;
+
+  const p = (async () => {
+    const healthy = await probe();
+    cached = {
+      healthy,
+      expires: Date.now() + (healthy ? HEALTHY_TTL_MS : UNHEALTHY_TTL_MS),
+    };
+    return healthy;
+  })();
+  inflight = p;
+  p.finally(() => {
+    if (inflight === p) inflight = null;
+  });
+  return p;
+}
+
+export function resetCmsHealthCache(): void {
+  cached = null;
+}
diff --git a/src/lib/maintenance.server.ts b/src/lib/maintenance.server.ts
new file mode 100644
index 0000000..3fd7064
--- /dev/null
+++ b/src/lib/maintenance.server.ts
@@ -0,0 +1,61 @@
+/**
+ * Statisches Maintenance-HTML für CMS-Ausfälle.
+ * Selbsttragend: keine CMS-Calls, kein Layout, inline CSS.
+ */
+const MAINTENANCE_HTML = `<!doctype html>
+<html lang="de">
+<head>
+<meta charset="utf-8">
+<meta name="viewport" content="width=device-width,initial-scale=1">
+<meta name="robots" content="noindex,nofollow">
+<title>Wartungsarbeiten — windwiderstand.de</title>
+<link rel="icon" type="image/svg+xml" href="/favicon.svg">
+<style>
+  :root { color-scheme: light; }
+  html, body { margin: 0; padding: 0; height: 100%; }
+  body {
+    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
+    background: #f8f7f3;
+    color: #18181b;
+    display: flex; align-items: center; justify-content: center;
+    min-height: 100vh; padding: 1.5rem;
+  }
+  .card { max-width: 36rem; text-align: center; }
+  .badge {
+    display: inline-block; padding: 0.25rem 0.75rem; border-radius: 9999px;
+    background: #e7f2ea; color: #2d7a45;
+    font-size: 0.875rem; font-weight: 600; letter-spacing: 0.025em;
+    margin-bottom: 1.25rem;
+  }
+  h1 {
+    font-size: clamp(1.75rem, 4vw, 2.5rem);
+    margin: 0 0 0.75rem; color: #18181b; font-weight: 700;
+  }
+  p {
+    font-size: 1.0625rem; line-height: 1.6; color: #52525b;
+    margin: 0 0 0.75rem;
+  }
+  .small { font-size: 0.875rem; color: #71717a; margin-top: 1.5rem; }
+  a { color: #2d7a45; }
+</style>
+</head>
+<body>
+<main class="card" role="main">
+  <span class="badge">Wartungsmodus</span>
+  <h1>Wir sind gleich zurück.</h1>
+  <p>Diese Seite wird gerade aktualisiert oder ist vorübergehend nicht erreichbar. Bitte versuche es in wenigen Minuten erneut.</p>
+  <p class="small">Vielen Dank für deine Geduld.</p>
+</main>
+</body>
+</html>
+`;
+
+export function maintenanceResponse(status: 200 | 503 = 503): Response {
+  const headers: Record<string, string> = {
+    'content-type': 'text/html; charset=utf-8',
+    'cache-control': 'no-store',
+    'x-robots-tag': 'noindex, nofollow',
+  };
+  if (status === 503) headers['retry-after'] = '60';
+  return new Response(MAINTENANCE_HTML, { status, headers });
+}