Responsive Notifications Page using Flexbox

What are you most proud of, and what would you do differently next time?

I would take the time to figure out how exactly I want to proceed with my JavaScript first.

What challenges did you encounter, and how did you overcome them?

I struggled with coming up with names for my classes. This might seem like a small issue but it's an issue for me. I just can't seem to come up with good, descriptive names and I don't know if there is a particular naming convention to work with. Any help/feedback/criticism would be highly appreciated.

Thank you so much.