When the user switches themes, popovers do not adapt for current page

[Jaifroid]

When the user switches to dark or light themes, popovers do not get re-styled until the user loads a new article (or re-loads the current article).

[Jaifroid]

This will affect KJS upstream as well. The problem is that different popover styling is loaded on page load. It could be solved by reloading the current article, but that would be a clunky experience. It would be better to remove the current styles and load the new ones. Or else find a way for the CSS of the popovers to respond to the theme of the page automatically.