        // 2. Fallback to origin server (exact file)
        if (CONFIG.ENABLE_FALLBACK) {
            try {
                const originResponse = await fetch(request);

                if (originResponse.ok) {
                    const headers = new Headers(originResponse.headers);
                    headers.set('cache-control', 'public, max-age=' + CONFIG.CACHE_TTL);
                    headers.set('x-staticq-source', 'origin');
                    headers.set('x-staticq-cache', 'MISS');

                    const response = new Response(originResponse.body, {
                        status: originResponse.status,
                        headers: headers
                    });

                    ctx.waitUntil(cache.put(cacheKey, response.clone()));
                    return response;
                }
            } catch (e) {
                console.error('StaticQ origin error:', e.message);
            }
        }
