I discovered that the layout of my website is (strongly) connected to the frame of my browsers window.
My friend send me pictures of her viewing the website. She has a Macbook Pro 13inch and her standard browers settings open a safari window not fully over the whole screen (like mine). Her browser shows it like this:
(Text and Images overlay)
Mine looks like this (Macbook Pro 15inch, standard safari browers window size takes the full screen) :
As I don't know what frame the browser window of my viewers have nor can control it, I wonder how I can solve/controll this issue.