server {
    listen 80;
    server_name _;

    client_max_body_size 200m;

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

    # SPA fallback — all routes serve index.html
    location / {
        try_files $uri $uri/ /index.html;
    }

    # Proxy API requests to backend — use variable to defer DNS resolution
    location /api/ {
        resolver 10.43.0.10 valid=5s;
        set $backend_upstream backend:8000;
        proxy_pass http://$backend_upstream;
        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 120s;
    }

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

    # Gzip
    gzip on;
    gzip_types text/plain text/css application/json application/javascript text/xml application/xml;
    gzip_min_length 256;
}