The site you list has another twist on the hover over theme but it's not hover over. That page is, overall, one of the most complex I've encountered in a long time.
It's difficult to know what to experiment with. If you have a specific control you'd like for me to explore to start let me know what it is.
Brian - Windows 10 Home, 64-Bit, Version 1803, Build 17134
A little kindness from person to person is better than a vast love for all humankind.
~ Richard Dehmel