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

    # Gzip compression
    gzip on;
    gzip_vary on;
    gzip_proxied any;
    gzip_comp_level 6;
    gzip_types text/plain text/css application/json application/javascript text/xml application/xml text/javascript image/svg+xml;

    # Health check
    location /health {
        access_log off;
        return 200 '{"status":"ok"}';
        add_header Content-Type application/json;
    }

    # API proxy
    location /api/ {
        proxy_pass http://api:3000;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
    }

    # Socket.IO proxy
    location /socket.io/ {
        proxy_pass http://api:3000;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    }

    # Static assets caching
    location /assets/ {
        expires 1y;
        add_header Cache-Control "public, immutable";
    }

    # SPA fallback
    location / {
        try_files $uri $uri/ /index.html;
    }
}