diff --git a/conf/nginx/dev4.4nkweb.com-https.conf b/conf/nginx/dev4.4nkweb.com-https.conf
index 709b129..3c85e32 100644
--- a/conf/nginx/dev4.4nkweb.com-https.conf
+++ b/conf/nginx/dev4.4nkweb.com-https.conf
@@ -11,6 +11,15 @@ server {
     ssl_certificate     /etc/letsencrypt/live/dev4.4nkweb.com/fullchain.pem;
     ssl_certificate_key /etc/letsencrypt/live/dev4.4nkweb.com/privkey.pem;
 
+    # Security headers (basic hardening)
+    add_header Strict-Transport-Security "max-age=31536000; includeSubDomains; preload" always;
+    add_header X-Frame-Options "SAMEORIGIN" always;
+    add_header X-Content-Type-Options "nosniff" always;
+    add_header Referrer-Policy "no-referrer" always;
+    add_header Permissions-Policy "geolocation=(), microphone=(), camera=()" always;
+    # Minimal CSP allowing Next.js static and same-origin; adjust later if needed
+    add_header Content-Security-Policy "default-src 'self'; img-src 'self' data: blob:; script-src 'self' 'unsafe-inline' 'unsafe-eval'; style-src 'self' 'unsafe-inline'; connect-src 'self' https: wss:; font-src 'self' data:" always;
+
     # ihm_client (root)
     location / {
         proxy_pass http://127.0.0.1:3003;
@@ -29,17 +38,42 @@ server {
         expires 30d;
     }
 
+    # Static assets long cache (root and /lecoffre)
+    location ~* ^(/_next/static/|/lecoffre/_next/static/|/.+\.(?:css|js|png|jpg|jpeg|gif|svg|ico|webp|woff2?))$ {
+        expires 30d;
+        add_header Cache-Control "public, max-age=2592000, immutable" always;
+        proxy_pass http://127.0.0.1:3000$request_uri;
+        proxy_set_header Host $host;
+        proxy_set_header X-Forwarded-Proto https;
+        proxy_read_timeout 300;
+    }
+
     # lecoffre-front
     location /lecoffre/ {
         proxy_pass http://127.0.0.1:3000/;
         include /etc/nginx/proxy_params;
-        # Sub-filter to ensure assets/links are prefixed with /lecoffre
-        proxy_set_header Accept-Encoding "";
-        sub_filter_types text/html application/javascript text/css;
-        sub_filter_once off;
-        sub_filter 'href="/' 'href="/lecoffre/';
-        sub_filter 'src="/' 'src="/lecoffre/';
-        sub_filter 'content="/' 'content="/lecoffre/';
+        proxy_set_header Host $host;
+        proxy_set_header X-Forwarded-Proto https;
+        proxy_set_header X-Forwarded-Host $host;
+        proxy_set_header X-Forwarded-Prefix /lecoffre;
+        proxy_read_timeout 300;
+    }
+
+    # Next.js assets and HMR under basePath
+    location /lecoffre/_next/webpack-hmr {
+        proxy_http_version 1.1;
+        proxy_set_header Upgrade $http_upgrade;
+        proxy_set_header Connection "upgrade";
+        proxy_set_header Host $host;
+        proxy_set_header X-Forwarded-Proto https;
+        proxy_buffering off;
+        proxy_pass http://127.0.0.1:3000/_next/webpack-hmr;
+        proxy_read_timeout 600s;
+    }
+
+    location /lecoffre/_next/ {
+        proxy_pass http://127.0.0.1:3000/_next/;
+        include /etc/nginx/proxy_params;
         proxy_read_timeout 300;
     }