FAQ Accordion Card

This was a really good challenge, introduced me to how useful changing classnames with DOM is and how to implement some animations although I still have 2 problems I need help with.

1. I haven't found a simple way to make it so everytime I open a different FAQ question the others close automatically, every solution I found uses Jquery or Bootstrap and not plain javascript, so currently you have to close each one individually otherwise if you open all of them it messes up the positioning and looks.
2. On the solution is shows the corner of the left image is hidden behind the background, there might be a way to do this with overflow, but I couldn't figure it out and I tried hiding it with z-index but I had no luck because then the background would be a higher z-index than the img and hide everything.

If you have any tips or solutions I would be very happy to have input of any kind.

Thanks!