overlay

README.md

@@ -46,6 +46,12 @@ Pages that are not prerendered (unlisted cities, GPS coordinate routes like
 and resolves the location client-side. Configure the server to serve
 `404.html` for unknown paths.
 
+Serve it as an **internal rewrite (200)**, not as an error page. `error_page
+404 /404.html` sends the right body with a 404 status: the page works, but
+every hard reload of an unprerendered URL logs a 404 in the network panel and
+tells crawlers the page does not exist. `try_files` with a URI as its last
+argument does an internal redirect instead, and answers 200.
+
 ### 2. Cross-origin isolation (SharedArrayBuffer for the embedded map)
 
 The `/weather/maps/` page embeds `maps.open-meteo.com`, which uses
@@ -83,11 +89,12 @@ drizzli.example.com {
 server {
 	server_name drizzli.example.com;
 	root /srv/drizzli;
-	error_page 404 /404.html;
 	add_header Cross-Origin-Opener-Policy "same-origin" always;
 	add_header Cross-Origin-Embedder-Policy "require-corp" always;
 	location / {
-		try_files $uri $uri/ =404;
+		# the trailing /404.html is a URI, so nginx rewrites internally and
+		# answers 200 - `error_page 404 /404.html` would answer 404 instead
+		try_files $uri $uri/index.html /404.html;
 	}
 }
 ```