I was playing online with someone I do not know that is considerably better than me. I am still somewhat new and I can't figure out why they would resign after castling. What am I missing?
[fen ""]
1.e4 g6
2.Nf3 Bg7
3.d4 d6
4.Nc3 a6
5.Bf4 Nd7
6.Bc4 e6
7.O-O Ne7
8.Bg5 h6
9.Bxe7 Qxe7
10.Qd3 b6
11.d5 e5
12.g4 Nc5
13.Qe3 Bxg4
14.h3 Bxh3
15.Rfe1 O-O 1-0