server {
    listen 3000;
    server_name localhost;
    root /usr/share/nginx/html;
    index index.html;

    # Handle React Router
    location / {
        try_files $uri $uri/ /index.html;
    }

    # Cache static assets
    location /static/ {
        expires 1y;
        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 X-XSS-Protection "1; mode=block" always;
}