Font and font size of menus and sliders

Font and font size of menus and sliders: How can I reduce the font size of a specific menu? Currently, this refers to the top menu. How can I set the font for the menus? Currently, the font I selected for the titles isn't being applied. How can I set the font in the slider? It isn't using the same font as the titles. Development page: https://zosicefa.myhostpoint.ch