[Resuelto] Language-Switcher styling

Background of the issue:
I want it to be visible on which page the user finds themselves by having an active color in the language-switcher. I tried adding it through the language settings > menu language-switcher styling, as well as through added css but neither is working. Link to a page where the issue can be seen: enlace oculto

Symptoms:
The green just appears when hovering over the elements.

Questions:
How can I make the active language color appear without hovering?
Why is the CSS not applying as expected?