Aeros 1.0.4 hacking for threaded(not nested) comments, help!

So I have Aeros 1.0.4 (the really old version, lol.) and it would be a huge hassle to upgrade to a newer version, so I took the comments.php from another version and tweaked the css to work with it. But I didn’t like how nested comments were inside of the parent, so I’ve tried making them just indented under them. Buuuutttt, I’ve run into a problem. Look at this: https://books.unedible.com/wings/comment-page-1#comment-840.
Anybody know how to fix that?