server {
    listen 80;
    server_name rstack.online www.rstack.online;
    root /usr/share/nginx/html;
    index index.html;

    location / {
        try_files $uri $uri/ /index.html;
    }

    # Cache static assets
    location ~* \.(css|js|png|jpg|jpeg|gif|ico|svg|woff2?)$ {
        expires 7d;
        add_header Cache-Control "public, immutable";
    }

    # Security headers
    add_header X-Frame-Options "SAMEORIGIN" always;
    add_header X-Content-Type-Options "nosniff" always;
    add_header Referrer-Policy "strict-origin-when-cross-origin" always;
}