server {
    listen ${PORT};
    server_name _;
    root /usr/share/nginx/html;
    index index.html;

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

    # index.html — never cache (so deploys serve new chunk references)
    location = /index.html {
        add_header Cache-Control "no-cache, no-store, must-revalidate";
        add_header Pragma "no-cache";
        add_header Expires "0";
    }

    # Handle SPA routing - serve index.html for all routes
    location / {
        try_files $uri $uri/ /index.html;
    }

    # Cache hashed static assets (immutable — filenames change on rebuild)
    location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg|woff|woff2)$ {
        expires 1y;
        add_header Cache-Control "public, immutable";
    }
}