FAQ using JS, Flexbox, SCSS

Initially I was able to add all the css click changes on the questions using a single onclick function, although I was not able to close a previous question when clicking on a new one. This expanded the faq container which is not what I wanted. Now I have each previous faq close when clicking a new one but was not able to include the bold font class and arrow flip on click...

This seems pretty basic and a must learn technique. I may be going about this all wrong, if anyone has any pointers on how to achieve this it would be gratefully appreciated. Thanks!