server {
    listen 80;
    listen [::]:80;
    server_name _;
    
    root /usr/share/nginx/html;
    index index.html;

    # Security headers
    add_header X-Frame-Options "SAMEORIGIN" always;
    add_header X-Content-Type-Options "nosniff" always;
    add_header X-XSS-Protection "1; mode=block" always;
    add_header Referrer-Policy "strict-origin-when-cross-origin" always;

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

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

    # HTML files - no cache for dynamic updates
    location ~* \.html$ {
        expires -1;
        add_header Cache-Control "no-store, no-cache, must-revalidate";
    }

    # Main location block
    location / {
        try_files $uri $uri/ $uri.html =404;
    }

    # Custom error pages
    error_page 404 /404.html;
    location = /404.html {
        internal;
    }
}