The menu bar that appears to follow you is a popular trick on most websites nowadays and actually really easy to do in CSS.
First, figure out what component you want to stay at the top of the page and in its css attributes, I’ll use the header for example.
make sure in HTML you use <div class= “header”> and not simply the <header> tag
setting the position to “fixed” means that it stays put on the page. After that, voila! your header stays atop the page no matter how long you scroll.