<code> tags result in empty boxes

[fredlcore]

I'm having a problem with generating a PDF from my mkdocs documents because text in backticks (resulting in a <code> tag) are displayed as empty boxes. The html files generated in the site directory still look fine:

However, in the PDF it looks like this:

It doesn't even seem to be hidden text as selecting the page text and then copy-pasting it to a text editor doesn't show the text there as well.

This is the HTML code that is generated for this part of that file in the site directory:

<ol>
<li>Make sure that your heating system is <a href="supported_heating_systems.html">compatible</a> with BSB-LAN!</li>
<li><a href="https://github.com/fredlcore/BSB-LAN/archive/refs/heads/master.zip">Download</a> and unpack the current BSB-LAN version from the master repository or use <em>git</em> to <a href="https://github.com/fredlcore/BSB-LAN.git">clone</a> the repository.</li>
<li>Navigate to the BSB_LAN folder and rename the following files:<ol>
<li><code>BSB_LAN_custom_defs.h.default</code> to <code>BSB_LAN_custom_defs.h</code></li>
<li><code>BSB_LAN_config.h.default</code> to <code>BSB_LAN_config.h</code>.</li>
</ol>

This is the CSS for the <code> tag in site/css/base.css:

code {
    padding: 2px 5px;
    background-color: rgba(var(--bs-body-bg-rgb), 0.75);
    border: solid 1px var(--bs-border-color);
    color: var(--bs-body-color);
    white-space: pre-wrap;
    word-wrap: break-word;
}

These are the mkdocs.yaml and extra style.css that I'm using, just to show that I don't make any changes to the <code> tag there:

site_name: BSB-LAN
theme: mkdocs
site_url: https://docs.bsb-lan.de
use_directory_urls: false

extra_css:
  - style.css

markdown_extensions:
  - attr_list
  - pymdownx.snippets

plugins:
  - search
  - with-pdf
  - autorefs
  - i18n:
      reconfigure_search: true
      docs_structure: folder
      languages:
          - locale: en
            name: English
            build: true
            default: true
          - locale: de
            name: Deutsch
            build: true
            nav_translations:
                Overview: Überblick
                Quickstart: Schnellstart
                How it works: Wie funktioniert's?
                Supported Heating Systems: Unterstützte Heizungssysteme
                The BSB-LAN Adapter: Der BSB-LAN Adapter
                The BSB/LPB/PPS Bus: Der BSB/LPB/PPS Bus
                How to set it up: Installation
                Installation: Zusammenbauen
                Configuration: Konfiguration
                ChangeLog: ChangeLog
                How to use it: Was kann es?
                BSB-LAN's functions: BSB-LAN Funktionen
                Connect to your Smart Home: Mit dem Smart Home verbinden
                Help!: Hilfe!
                Troubleshooting: Fehlersuche
                FAQ: FAQ
                Wiki: Wiki
                YouTube Tutorials: YoutTube Tutorials
          - locale: fr
            name: Français
            build: true
            nav_translations:
                Overview: Aperçu
                Quickstart: Démarrage rapide
                How it works: Comment ça marche?
                Supported Heating Systems: Systèmes de chauffage pris en charge
                The BSB-LAN Adapter: L'adaptateur BSB-LAN
                The BSB/LPB/PPS Bus: Les BSB/LPB/PS bus
                How to set it up: Installer
                Installation: Assemblage
                Configuration: Configuration
                ChangeLog: ChangeLog
                How to use it: Utiliser
                BSB-LAN's functions: Fonctionnes de BSB-LAN
                Connect to your Smart Home: Connecter à la Smart Home
                Help!: Au secours!
                Troubleshooting: Dépannage
                FAQ: FAQ
                Wiki: Wiki
                YouTube Tutorials: YouTube tutoriels

nav:
  - Overview: README.md
  - Quickstart: quickstart.md
  - How it works:
    - Supported Heating Systems: supported_heating_systems.md
    - The BSB-LAN Adapter: bsb-lan_adapter.md
    - The BSB/LPB/PPS Bus: bus_systems.md
  - How to set it up:
    - Installation: install.md
    - Configuration: configure.md
    - ChangeLog: CHANGELOG.md
  - How to use it:
    - BSB-LAN's functions: using.md
    - Connect to your Smart Home: homeautomation.md
  - Help!:
    - Troubleshooting: troubleshooting.md
    - FAQ: faq.md
    - Wiki: "https://github.com/fredlcore/BSB-LAN/wiki"
    - YouTube Tutorials: "https://www.youtube.com/@BSB-LAN"
  - 🌐:
    - Deutsch: /de/
    - English: /
    - Français: /fr/

h1, h2, h3 {
    color: rgb(84, 162, 225);
}

h1, h2 {
    font-weight: bold;
}

em {
    font-variant: small-caps;
    font-style: normal;
}

body::before {
    background: white;
}

a {
    font-weight: bold;
}

It would be great if you could help me out here because otherwise, your plugin produces really great results and I'd love to use it for my project!

[fredlcore]

To provide some additional information: The text is actually present, but it's font size must be 1 or something like that because it is just a few pixels high, and it's color is the same as the background, so it's not visible. I have tried running it with the debug_html and verbose options, but the information is too much for me to make any sense of it...

[fredlcore]

After unsetting and re-enabling all CSS properties, I found the culprit. Adding this into my extra style.css displayed the text within the backticks:

code {
    font-weight: bolder;
}

Interestingly, it has to be bolder. normal or unset does not do the trick.