Problem with the "blog" page and footer

Hello, problem with the “blog” page
https://www.gamestep.fr/blog/

– Article 2 goes over Article 1 (see screenshot 1)
– So, big space between article 2 and article 3 (see screenshot 2)
– And to finish big space between end of the page and footer on all the page of the site, not only on the blog page. (screenshot 3)

Thanks in advance.