Weight loss/toning

SO I wasn't really sure where to post this so sorry if it's in the wrong place just looking for advice. I'm 5'5/5'6 and usually weight around 140lbs. I wouldn't consider myself 'fat' but I do have a bit of a tummy on me. I think I have a somewhat 'curvy' figure with wide hips etc however I'm really struggling to tone my stomach!! The usual squats etc work great on my thighs and bum but I'm trying so hard to lose the stomach I have and it seems impossible. I've cut chocolate etc almost completely out my diet and eat pretty well