Project Landing Page - Nav Bar help

I have read the description for this project and I am confused on how to create a fixed navbar with only HTML and CSS. Can it actually be done without Javascript? I am curious if it is possible to do this without the use of JS to detect the scroll of the mouse.

you just need position: fixed; in css for your nav element

Sorry I feel like an idiot. I could have sworn I had done that but I just tried that and it worked. Thanks.