Does Arduino board have CMOS or TTL gates?
All the key facts about a chip should be contained in its datasheet. This should always be your first port of call when researching things.

Atmega328 datasheet.

Search for "CMOS". First hit is page 5:

"The ATmega48PA/88PA/168PA/328P is a low-power CMOS 8-bit microcontroller based on the
AVR enhanced RISC architecture".

Bonus answer: a quick look at the Arduino UNO schematic shows three different voltage regulators, and an LM358D used as a comparator, all of which are considered "analog" parts and neither CMOS nor TTL.