server {
    listen 80;
    server_name localhost;
    root /usr/share/nginx/html;
    index index.html;

    # Gzip compression
    gzip on;
    gzip_vary on;
    gzip_min_length 1024;
    gzip_types text/plain text/css text/xml text/javascript application/javascript application/xml+rss application/json;

    # Cache static assets
    location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg|woff|woff2|ttf|eot)$ {
        expires 1y;
        add_header Cache-Control "public, immutable";
    }

    # PWA manifest and service worker - no cache
    location ~* (manifest\.json|sw\.js)$ {
        expires -1;
        add_header Cache-Control "no-store, no-cache, must-revalidate";
    }

    # SPA fallback - all routes serve index.html
    location / {
        try_files $uri $uri/ $uri.html /index.html;
    }

    # 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;
}