my footer is being overlapped by my body text

I'm following a basic HTML tutorial on building a website, and I'm stuck on a part where she has told me to duplicate my article within my container (that's inside of the body), and on her website, the length of the container automatically adjusted, but on mine, it overlapped my footer and the container's background never extended. 

I tried adjusting the padding for the footer but it stays overlapped, and I tried the same with the container but it adjusts all of the articles in the container that I duplicated.

I'm mainly confused about why it's overlapping, but also why the container is auto-adjusting even though that's how I've coded it. My code is identical to the tutorial so some guidance would be appreciated.