For some reason, the prism.js code highlighter plugin does not work on the Quark base theme. It is rendering a <div> and not a code or pre block. I installed the same plugin on the learn2 theme and it renders correctly. I can not figure out why Quark changes this to a div while learn2 uses the code tag as it should.
I have tried toggling this setting in the plugin:
all-pre-blocks: false