Can I live comfortably (hotels, restaurants, train) directly using euro only?
Croatia joined the EU on the 1st of July 2013 but still didn't adopt the Euro as currency.
I googled a bit and I found out an interesting site about the currency used in Croatia.
From this site:
You will find that you can pay for some items - accommodation, taxis, some restaurants - in Euros. Do note that this is entirely on an unofficial basis; the Euro is NOT an official currency in Croatia and NO business/individual is required to accept them as payment. (It is just the case that some businesses, particularly small/family-run ones are happy to receive Euros - this probably harks back to the days of Yugoslavia when people were happier "holding" Deutschmarks rather than the unstable Yugoslav Dinar.)
So, it seems that Euros are accepted in certain cases but you should be prepared to pay in Kuna as well.
Officially: NO, because you have to be allowed to convert foreign currency first, if you want to be able to accept one. Often you may find people kindly rejecting Euro and they will explain that they would like to accept it, but it would be against the law.
However, as noted above, some individuals might accept it, as they know nobody will prosecute them.
So just for your understanding, you won't be able to buy anything with Euro in any big shops or government businesses, like public transport etc. You may be able to pay in SOME restaurants, thought.
I am currently travelling in Croatia, and have been for about two weeks. My experience has been that everyone accepts kuna, and some establishments also accept euro. The kuna is effectively pegged to the euro, so exchange rates have been consistent.
In the beginning of my travels here, I needed to buy a bus ticket to the airport, and the woman behind the counter did not accept euros. Luckily there was an ATM nearby, but she seemed to (understandably) feel annoyed that I hadn't bothered to use the country's currency.
My experience is that Euros are coveted there, so in general, nearly all stores and restaurants eagerly take them except government/official stores, like museums. Public transport (buses/ferries) will not take Euros. Of course, the exchange rate you will get from a store or restaurant will be much worse than what you would get at a cambio or bank.