Responsive FAQ landing page with flex and first time use of JS

My first time use of JS, it has been a fun project and difficult, but practice makes perfect!

If anyone can tell me how can I chop the image, on desktop view, so that the orange box can be added on top and stay there. I tried with position: static on the orange box but it would move around along the width of the viewport once it's changed. Any hint would be very welcome! Feedback also!