git

public/service-worker.js

@@ -43,10 +43,11 @@ self.addEventListener("notificationclick", (event) => {
   );
 });
 
-const CACHE_NAME = "pwa-cache-v11";
+const CACHE_NAME = "pwa-cache-v12";
 
 const PRECACHE_URLS = [
   "/",
+  "/offline.html",
   "/manifest.webmanifest",
   "/manifest.json",
   "/images/icons/192x192.png",
@@ -82,7 +83,9 @@ self.addEventListener("fetch", (event) => {
   const url = new URL(event.request.url);
 
   if (event.request.mode === "navigate") {
-    event.respondWith(fetch(event.request));
+    event.respondWith(
+      fetch(event.request).catch(() => caches.match("/offline.html"))
+    );
     return;
   }