The theme we use is a one-page theme. External links require us to add a CSS class to the link in the main menu, to actually have a link that leads away from the page.
With standard linked pages, individual links etc. you have a field where you can enter the name of an optional class, but for the language switcher menu entry, the CSS field is missing.
How can I add a CSS class manually to the language switcher main menu item?
EDIT: Alternatively, is there something I could add to an individual link added to the menu, to make it a ‘true’ language switch (instead of just calling another page).