This doesn’t really help. In mobile view the search box, language switcher run over the logo. One solution would be to have them at different levels, or to be able to hide the language switcher in mobil view altogether.

I am not experienced in editing anything myself, so: the php-thing: do i just paste it in t the end of the text in the view of the screen shot? When i tried to find the functions.php-file in ftp just to be able to back it up – just in case – i didn’t find it.