Apex domains cannot have CNAME records.
Question and response
Question
dig invitech.hu. NS
Answer
invitech.hu. 5 NS nsa2.isp.hu.
invitech.hu. 5 NS nsa1.isp.hu.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0