CSS for dropdown menu

Hello,

Thank you for your plugin! A previous post changing the CSS of the floating widget used the following code:

#glt-translate-trigger {

/*style*/

}

I want to add a focus element for the drop down menu like this for accessibility purposes

glt-translate-???:focus {

border: 3px solid white;
border-radius: 7px;

}

but I am unsure what to type that will control the language switcher. Thank you very much