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

    # Security headers
    add_header X-Frame-Options "SAMEORIGIN";
    add_header X-XSS-Protection "1; mode=block";
    add_header X-Content-Type-Options "nosniff";
    add_header Strict-Transport-Security "max-age=31536000";
    add_header Content-Security-Policy "default-src 'self'; script-src 'self' 'unsafe-inline' 'unsafe-eval' https://unpkg.com; style-src 'self' 'unsafe-inline'; img-src 'self' data: https:; font-src 'self' data:;";

    # Compression
    gzip on;
    gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript;

    location / {
        try_files $uri $uri/ /index.html;
        expires 1h;
        add_header Cache-Control "public, no-transform";
    }

    # Static asset caching
    location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg)$ {
        expires 30d;
        add_header Cache-Control "public, no-transform";
    }
}
