https://web.dev/articles/offline-fallback-page
Create an offline fallback page | web.dev
Sep 24, 2020 - Learn how to create a simple offline experience for your app.
offline fallbackpage webcreatedev
https://www.webapp2app.com/2026/04/01/offline-first-android-webview-local-html-fallback-smart-cache-and-auto-reconnect-with-webviewgold/
Offline-First Android WebView: Local HTML Fallback, Smart Cache, and Auto-Reconnect with...
offline firstandroid webview