I very much appreciate the suggestion, thank you! This is my very first venture into coding and I had no idea the max-width bit wasn't doing what I thought it was. I've added what you've said just as written, so I hope it's correct now, sitting with the rest of the post information.
I'm framing this compliment on my mental wall, as well. It's always nice to hear from someone else who loves The Railway Series and I'm glad I was able to give you a new perspective. These not-so-little creatures mean a whole lot to me, and I'm cheesed to know I'm onto something, haha!