Thanks for your quick Reply. I added the code in the css-file and it works! Even in the Edge-Browser when changing the window-width it’s adjusting and when it’s to small the Menu-Titel appears to open the Navigation.
Regarding the menu, there’s still one Problem. In case the width of browser-Window (Edge and IE11) is very small and once opened the menu to navigate to a page the menu is not reappearing:
Small Detail: The Descriptions for the comment-fields are shown in the Edge-Browser if the window-width is very small.