Counter Increment Issue
Hi as of now, I found out that the counter is not starting from the expected counter value. Anyway, I found a possible solution to fix that issue, unfortunately I don't know on how to implement it on your src code. But here is my solution:
On line 2467, the div.pagedjs_area (L#2500) should be the first child.
And here is the result:
Hope it can help you to fix the issue. Thank you so much!
Edit: Note that P[X]C[Y] is standing for [X] = Page Counter, [Y] Chapter Counter which is declared into a class.
Edit 2: Here is the testing file that I used - chapter.html