Responsive mobile-first FAQ Accordion

I would be deeply thankful for the feedback according:

• images positioning (maybe it can be improved by placing it as an img tag instead of using it as a background on a div?)

• logic of collapsibles in my main.js file (is there any way to improve event listener? I have found a lot of examples where listeners were attached in the loop, but maybe it is more effective to attach one listener on the items container and then kind of listen for the 'target' element that is being clicked?)