Mobile Image Container Size Issues

Hi everyone,

I have been trying to figure out why my “Slider” won’t slide correctly in the Twentyfourteen theme that’s responsive. I finally figured out that it is supposedly an image container size issue. I also noticed that this is an issue with the thumbnail images I have in my popular posts WordPress widget. I have already checked and confirmed the appropriate image sizes for the theme and still have the issues. Does anyone know how I can fix these issues?

The page I need help with: [log in to see the link]