Error with the width of elements on the responsive page

I had a problem with a page I’m developing. For some reason, when I readjusted the size of the page to test the responsiveness, in netbook resolutions, the content does not occupy the entire screen but only a part. The strange thing is that when inspecting the elements, they all appear to have the same width as the screen, when at first glance it seems that they do not.

I tried to assign it to occupy the entire width of the screen but it clearly didn’t work