# Standard Nginx top-level config
user  nginx;
worker_processes  auto;
error_log  /var/log/nginx/error.log notice;
pid        /var/run/nginx.pid;

events {
    worker_connections  1024;
}

http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;

    # --- THE FIX STARTS HERE ---
    # These MUST be in the http block to handle the IAP header early
    client_header_buffer_size 64k;
    large_client_header_buffers 4 64k;
    # --- THE FIX ENDS HERE ---

    sendfile        on;
    keepalive_timeout  65;

    server {
        listen 80;
        server_name _;

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

        location / {
            try_files $uri $uri/ /index.html;
            # Ensure headers are passed correctly
            proxy_set_header Host $host;
        }
    }
}