Setting specific CSS for different sized screens is wonderful. You can have have the website change in any way you want depending on the width of the screen.
I have been really interested in the media queries. I found it interesting that you could make specific website designs for specific sized websites. If you really wanted you could completely change the layout of the website so that it doesn’t even resemble the original design. Its pretty much strictly used for adjusting websites to fit smaller screen with very small changes to the design. I enjoyed learning about this because beforehand I didn’t know it was possible.