// Service Worker: Offline-Fallback für Portal-Selektor
const CACHE_NAME = 'portal-offline-v1';

self.addEventListener('install', event => {
  event.waitUntil(
    caches.open(CACHE_NAME).then(cache => cache.add('offline.html'))
  );
  self.skipWaiting();
});

self.addEventListener('activate', event => {
  event.waitUntil(
    caches.keys().then(names =>
      Promise.all(names.filter(n => n !== CACHE_NAME).map(n => caches.delete(n)))
    ).then(() => self.clients.claim())
  );
});

self.addEventListener('fetch', event => {
  if (event.request.mode === 'navigate') {
    event.respondWith(
      fetch(event.request).catch(() => caches.match('offline.html'))
    );
  }
});