Checkpoint: current working state

share/fallback.html

@@ -0,0 +1,33 @@
+<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="utf-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1" />
+    <title>Lumen — offline</title>
+    <meta name="color-scheme" content="light dark" />
+    <style>
+      body {
+        font-family: system-ui, sans-serif;
+        max-width: 40rem;
+        margin: 2rem auto;
+        padding: 0 1rem;
+        line-height: 1.5;
+      }
+      h1 {
+        font-size: 1.5rem;
+      }
+      .note {
+        border: 2px solid currentColor;
+        padding: 1rem;
+      }
+    </style>
+  </head>
+  <body>
+    <h1>Lumen</h1>
+    <p class="note" role="alert">
+      You are offline and the app shell is not cached. Emergency information is available from
+      festival staff and printed materials.
+    </p>
+    <p>When you are back online, open <a href="/">Lumen</a> to reload the app shell.</p>
+  </body>
+</html>