In some places, a separate handling of hovering an element was implemented, as the CSS pseudo class :hover probably did not yet exist at this time.
This implementation realizes the functionality by overwriting all CSS classes with a CSS class that contains "hover" in its name.
This behavior leads to unexpected effects and is usually neither desirable nor a good implementation.
Therefore, all places with this implementation have been replaced by simple CSS classes with :hover.
The following CSS classes had to be replaced:cmdButtonHover of command buttons (e.g. edit in the footer), menuEntryHover and the general class Hover.
Test
Move the mouse over elements such as command buttons (e.g. Edit in the footer) or menu entries in pop-up menus (popupMenu, e.g. developer options). When hovering, you should now see the same effect as before (e.g. font/background color change).