server {
    listen 80;
    server_name _;

    root /usr/share/nginx/html;
    index index.html;

    gzip on;
    gzip_vary on;
    gzip_min_length 1024;
    gzip_types text/plain text/css application/javascript application/json image/svg+xml;

    location = /healthz {
        access_log off;
        default_type text/plain;
        return 200 "ok";
    }

    # API traffic → FastAPI backend (compose service `api` on :8000)
    location /api/ {
        proxy_pass http://api:8000;
        proxy_http_version 1.1;
        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;
        proxy_read_timeout 60s;
    }

    # Hashed build assets: cache aggressively
    location /assets/ {
        expires 30d;
        add_header Cache-Control "public, max-age=2592000, immutable";
        try_files $uri =404;
    }

    # SPA fallback; never cache the HTML shell
    location / {
        try_files $uri $uri/ /index.html;
        add_header Cache-Control "no-store";
    }
}