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

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

    # Security headers
    add_header X-Content-Type-Options "nosniff" always;
    add_header X-Frame-Options "DENY" always;
    add_header Referrer-Policy "strict-origin-when-cross-origin" always;
    add_header Permissions-Policy "camera=(), microphone=(), geolocation=(), interest-cohort=()" always;
    add_header Content-Security-Policy "default-src 'none'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self'; font-src 'self'; connect-src 'self'; base-uri 'self'; form-action 'self'; frame-ancestors 'none'" always;
    add_header Strict-Transport-Security "max-age=63072000; includeSubDomains; preload" always;

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

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

    # Custom error pages
    error_page 404 /404.html;
}