Inconsistent chapter numbering (PDF, HTML) when using proposed Preface in index.qmd

[fuhrmanator]

In a book project, I'm struggling with making a Preface that is unnumbered (like in most books) in both the PDF and the HTML. I followed the sample that got created when I made the project (it was a much older version of Quarto!) and it suggested a Preface in index.qmd that looked like:

# Preface {.unnumbered}

Blah blah...

In the PDF, this works great. The Preface doesn't have a number (I think it probably is 0 in LaTeX, but that number is hidden), and the first chapter is the following chapter.

However, when I view the HTML version of the book, the Preface has a 1 in the left navigation window, and the intended "first" chapter (in my PDF) is now a chapter 2 in the HTML. For users (students) of my manual, this will be confusing.

How can I get the same numbering in HTML and PDF? Or how can I do a Preface that has no number?

Things I've tried:

• making index.qmd include a Preface.qmd (I found it's easier for maintaining the book to know what goes where). However, when the navigation to the left (HTML) is created, it shows "index" rather than Preface.
• not using index.qmd (results in an error, it's required). The documentation about book projects at https://quarto.org/docs/books/book-structure.html does not say much about it.
• making a blank index.qmd and having the unnumbered Preface in a following chapter Preface.qmd. This results in a totally empty chapter 1.

[fuhrmanator]

Finally, this is not a problem anymore. I'm not sure what happened, but my PDF and HTML renderings are again consistent. At some point I had a bunch of HTML files generated in the top-level directory (as if Quarto wasn't finding the _quarto.yml file). Perhaps it was because I did a render using CTRL-SHIFT-K in the wrong .qmd file. Anyway, sorry for the noise here.