### Bug description

Is this a bug or am I doing something incorrect?

quarto version: 1.3.203
Windows 10
deno 1.30.3 (release, x86_64-pc-windows-msvc)
v8 10.9.194.5
typescript 4.9.4

1) Created a new book
```
C:\sw>quarto create-project qbook2 --type book
Creating project at G:\gdac\qbook2:
  - Created _quarto.yml
  - Created index.qmd
  - Created intro.qmd
  - Created summary.qmd
  - Created references.qmd
  - Created cover.png
  - Created references.bib
```

2) started local preview without modifications.

```
C:\sw>cd qbook2

C:\sw\qbook2>quarto preview
Preparing to preview
[1/4] index.qmd
[2/4] intro.qmd
[3/4] summary.qmd
[4/4] references.qmd

Watching files for changes
Browse at http://localhost:3286/
GET: /
GET: /intro.html
GET: /intro.html
GET: /summary.html
GET: /intro.html
GET: /intro.html
```

### Desktop Mode: Chapter 1 Introduction heading is displayed properly.

![image](https://user-images.githubusercontent.com/7158596/219428463-3b0cf0b0-b5c3-4ac7-a6e8-dbc3ed7d2708.png)

### Mobile Mode: Chapter 1 Introduction heading is displaying its code as a string. 

![image](https://user-images.githubusercontent.com/7158596/219428937-9b09d004-d805-44cd-8d33-db7d5433c008.png)

![image](https://user-images.githubusercontent.com/7158596/219429134-b11fdf96-eb5a-407b-a88c-7c28128baacc.png)

"Preface" and "References as headings display properly but Chapters don't display properly in mobile or responsive mode.

```html
<ol class="breadcrumb">
  <li class="breadcrumb-item">
    <a href="http://localhost:3286/intro.html">&lt;span class='chapter-number'&gt;1&lt;/span&gt;&nbsp; &lt;span class='chapter-title'&gt;Introduction&lt;/span&gt;</a>
  </li>
</ol>
```

### Similar for Chapter 2 in mobile mode.

![image](https://user-images.githubusercontent.com/7158596/219430709-fbee6e93-e26d-4bcf-ade8-5a1edd4df3dc.png)


### Checklist

- [X] Please include a minimal, fully reproducible example in a single .qmd file? Please provide the whole file rather than the snippet you believe is causing the issue.
- [X] Please [format your issue](https://quarto.org/bug-reports.html#formatting-make-githubs-markdown-work-for-us) so it is easier for us to read the bug report.
- [x] Please document the RStudio IDE version you're running (if applicable), by providing the value displayed in the "About RStudio" main menu dialog?
- [X] Please document the operating system you're running. If on Linux, please provide the specific distribution.
dragonstyle
2023-02-16T16:45:19Z
fortunewalla
bug
v1.3
closed
quarto create-project new book preview breaks chapter heading in mobile responsive mode
https://github.com/quarto-dev/quarto-cli/issues/4388