Adjust Video for Mobile Layout

Hey everyone, I’m currently building my portfolio using Readymag, and I’m about to finish the desktop view of the website. One of my favorite parts of the site is the short videoclips that keep looping in the background. Today, I wanted to start working on the mobile version of the site, but I’m having trouble changing the position of the videos. Additionally, there’s no way to upload a different video for the mobile view. Does anyone have any ideas on how I can fix this problem or at least change the position of the video in the background?

big thx in advance <3