I'm sure I should be able to fix this myself, I'm just having a stupid moment. And yes, I'm well aware there's a post just a few down of someone with the same problem, and I did read it, and still couldn't figure it out, so I thought I'd better post.
I've spent the evening redoing my journal layout. I've just about got everything the way I want it now, apart from the leave comment page. The reply box is too wide, and I can't figure out how to fix it.
As I said, it's almost certainly just me being stupid, but I can't figure out what I've missed, and it's really bugging me.
My layer code