Side-scrolling website and responsivness

Hi there,
I’m working on a site that is side-scrolling. I started with a template that I modified and I don’t know were I made mistakes but I can’t seem to understand how to make sure that my content fits in different screen resolution. To be more precise, my goal would be to understand what setting I could change to make sure that my content doesnt «overflow». As you can see in this screenshot, some content is not shown when I’m on a laptop. When I’m on a larger screen everything is fine.

thank you very much :slight_smile:

Here is my site Read-Only: