Accordion FAQ fully done by css using element (thanks Grace)

Is there a way to make it more beautiful?

I've done the accordion using only css and <details> element. My main issue is that when I click on a new question the previous answers don't collapse (which is quite annoying for me). I've tried using only css without any js for the bonus points. On StackOverflow people answered that they believe that it could be done only by js.

Essential, for the above-mentioned reason I needed to make a height bigger than usual, which doesn't look nicely when all the answers are collapsed.