Apex domains cannot have CNAME records.
Question and response
Question
dig ghostnet.de. NS
Answer
ghostnet.de. 5 NS sue.ns.cloudflare.com.
ghostnet.de. 5 NS phil.ns.cloudflare.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0