A 1-0 win for Croatia against Malta combined with Italy's 2-1 victory over Norway saw the Balkan nation through to next year's tournament in France as runners-up to the Azzurri in Group H.
Croatia were two points adrift of Norway in the race for second place prior to kick-off but results went the way of Srna and his colleagues.
Speaking afterwards via Uefa.com, Srna felt his team-mates deserved for praise for the way in which they had reacted to the criticism they had received after last month's 2-0 loss in Oslo.
Getty Images"Today Croatian players are heroes who are doing everything they can for their country," he stated. "Tonight [Tuesday], it's time to celebrate.
"We are proud that we will listen to the Croatian anthem in France at Euro 2016.
"We have a number excellent Croatian players and I am not afraid about our future."
Ivan Perisic's 25th-minute strike was all that Croatia needed against minnows Malta in Ta' Qali.
Croatia will now feature at a fourth consecutive European Championship, while they have reached nine of the past 11 major tournaments.
Ante Cacic, who replaced Niko Kovac last month following the loss in Norway on September 6, added: "It's a wonderful feeling. I have to congratulate my team, the former coach and all the people who were supporting Croatia.
"We played a good qualifying campaign and beside two bad results we fulfilled our expectations.
"Now it is time to celebrate this, there were hugs and singing after the match, we are all happy and proud.
"When Norway scored in Rome, I told my players at half-time that we have to concentrate on our match and that Italy would score two goals in the second half."
