FAQs using Html ,CSS and JS

I find the CSS part a bit difficult but as a beginner it's fine. we learn by doing the difficult things. I am unsure about the responsive part of the CSS media query code I have Questions about a project that I made. Do you think this project needs some refinement? and what about the javascript part I was thinking of it when I clicked the plus icon the other answer which is opened should close but I was unable to think of that, please suggest to me if you know I would be very thankful if you help me!