diff --git a/src/gateway/public-gateway.mjs b/src/gateway/public-gateway.mjs
index 92736a1..a5627e6 100644
--- a/src/gateway/public-gateway.mjs
+++ b/src/gateway/public-gateway.mjs
@@ -234,7 +234,17 @@ async function serve(res, name, reqPath, baseHref) {
                   : reqPath.endsWith("/") ? reqPath.slice(1) + "index.html"
                   : reqPath.slice(1);
         const key = base.endsWith("/") ? base + rel : base;
-        const up = await aws.fetch(`${S3_ENDPOINT}/${key}`);
+        let up = await aws.fetch(`${S3_ENDPOINT}/${key}`);
+        // SPA fallback — if the extension-less path 404s, serve the domain's
+        // own index.html so client-side routers (History API) can pick up
+        // /katalogos, /anthemus, /artemision, etc. under any BNS mount.
+        // We only fall back when the requested path has no file extension —
+        // requests for missing images / json / js still 404 as they should.
+        if (up.status === 404 && !/\.[a-z0-9]+$/i.test(reqPath) && reqPath !== "/") {
+          const fallbackKey = (base.endsWith("/") ? base : base + "/") + "index.html";
+          const fb = await aws.fetch(`${S3_ENDPOINT}/${fallbackKey}`);
+          if (fb.ok) { up = fb; }
+        }
         const buf = Buffer.from(await up.arrayBuffer());
         let ct = up.headers.get("content-type"); if (!ct || ct === "application/octet-stream") ct = guess(key);
         if (ct.includes("text/html")) { res.writeHead(up.status, { "content-type": ct }); return res.end(injectBase(buf.toString("utf8"), baseHref)); }