feature: per-document `title-block-style: default`

Bug description

I set up a standard Quarto website (https://quarto.org/docs/websites/). One page (here, index.html) should use title-block-style: none, a second page (here about.qmd) should use title-block-style: default. However, when I re-render the website (either using quarto render or quarto preview) the page that uses title-block-style: default occasionally does not look as expected (see below). Re-rendering the website again "solves" the problem (see below). While this is generally not a big issue, I noticed that it also occasionally happens for some of my larger Quarto projects where I deploy websites to GitHub Actions / Pages. All pages with title-block-style: default look weird (see below). The problem is that I haven't found a way to control the deployment GitHub Actions so that this issues does not occur.

Steps to reproduce

I prepared an example here: https://github.com/lnnrtwttkhn/quarto-title-block-style. I deliberately also tracked the changes in _site.

The issue seems to be related to _site/site_libs/bootstrap/bootstrap.min.css that "fluctuates" upon frequent re-rendering.

• Here is a commit where the page looked as expected: https://github.com/lnnrtwttkhn/quarto-title-block-style/commit/6dad9153c8dc827f0e83cf9eb097df6116faac18
• Here is a commit where the page looks unexpected: https://github.com/lnnrtwttkhn/quarto-title-block-style/commit/b99ffa09b3c1fa22f8bcb5a300538de3f9462d61

I haven't yet fully figured out a pattern when this occurs exactly but it happens both for quarto render and quarto preview.

Expected behavior

The page with title-block-style: default should look as expected:

Actual behavior

The page with title-block-style: default does not look as expected:

Your environment

• IDE: RStudio Version 2023.12.1+402 (2023.12.1+402)
• macOS 14.3.1 (Sonoma)
• Hardware: Apple MacBook Pro 14-inch, 2021, 16 GB RAM

Quarto check output

quarto check

[✓] Checking versions of quarto binary dependencies...
      Pandoc version 3.1.1: OK
      Dart Sass version 1.55.0: OK
[✓] Checking versions of quarto dependencies......OK
[✓] Checking Quarto installation......OK
      Version: 1.3.450
      Path: /Applications/quarto/bin

[✓] Checking basic markdown render....OK

[✓] Checking Python 3 installation....OK
      Version: 3.12.2
      Path: /opt/homebrew/opt/python@3.12/bin/python3.12
      Jupyter: (None)

      Jupyter is not available in this Python installation.
      Install with python3 -m pip install jupyter

[✓] Checking R installation...........OK
      Version: 4.3.1
      Path: /Library/Frameworks/R.framework/Resources
      LibPaths:
        - /Users/wittkuhn/tools/quarto-title-block-style/renv/library/R-4.3/aarch64-apple-darwin20
        - /Users/wittkuhn/Library/Caches/org.R-project.R/R/renv/sandbox/R-4.3/aarch64-apple-darwin20/84ba8b13
      knitr: 1.45
      rmarkdown: 2.26

[✓] Checking Knitr engine render......OK