So I just wasted a morning trying to debug why the Highlight.js syntax highlighting in Kitten suddenly began to fail only to realise that @1password is stripping the hljs- prefixes from the class names.
You can see this for yourself if you have the 1password extension installed at:
https://kitten.small-web.org/#the-ubiquitous-counter-example
Load that page with 1password enabled in your browser and you will see that the syntax highlighting doesn’t work and the hljs- prefixes have been stripped.
Disable the 1password extension and load the page again and you will see syntax highlighting working properly.
WTF?!