Apex domains cannot have CNAME records.
Question and response
Question
dig vip.hr. NS
Answer
vip.hr. 5 NS dns2.vip.hr.
vip.hr. 5 NS dns1.vip.hr.
Authority
The response has no authority records.
Additional
dns1.vip.hr. 5 A 212.91.97.5
dns2.vip.hr. 5 A 212.91.97.6
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0