Tooltip styles changed and not responding to modifications in settings

Hadn’t had time to visit my Website in a while: the Glossary plugin is not working like before regarding the style of links and tooltips that have radically changed without me changing anything in the settings. (And even if I try to modify the settings these new (ugly and sometimes illegible) styles will not revert to their previous look!)
– all words linked are now highlighted with a grey background
– tooltips have a hardly readble black backgrounds even if try to put them in white in the settings
– the content of tooltips on words that are in a title have a huge font size and so are not legible anymore
I have the latest versions of WP and Glossary… at least I think so (I am an individual premium user).
What happened? How can I fix this?

Thank you for your help!

P.-S. I will have more questions later since I will be doing an English version of my (currently French only) Website: will I be able to separate the two differents versions of the Website so that there is a separate page of definitions for the English version and so that words spelled the same way in both languages get seprate entries? But this is another question, sorry. I can ask you again later. The priority for now is to reinstate the original styles for words and tooltips

The page I need help with: [log in to see the link]