Thanks for your reply, but the hover state is NOT working as I would like. I cannot achieve what I wanted and overrule what you have with !important. Of course, I could be missing something, so welcome your advice.
Your base CSS takes a background color (end-user ability to set this color in customization), & sets to low opacity at “resting” state. On hover, that color changes to a higher state of opacity.
What I wanted was to have low opacity of base purple color (in my case #54397e) go to a fairly opaque blue (#0d5e9c) rather than opaque purple.
The code I copy and pasted was my attempt to do that, but whatever color I add to the hover-state CSS changes the color of all states. If to_top_scrolltotop background-color is blue, the “resting” state (:active, :visited) is a low opacity blue not of purple. If I remove the hover state CSS it’s all varying degrees of the purple.
So, seeking different opacity AND color on hover. Thank you, Skandha