The kind of whizzbangs associated with "beautiful UI" often involves copious amounts of JavaScript hijacking scroll events, running code for every pixel of a mo

The kind of whizzbangs associated with "beautiful UI" often involves copious amounts of JavaScript hijacking scroll events, running code for every pixel of a mouse move, and so on. Something as simple as "header in the middle of the page" can involve an absolutely-positioned header moved around on scroll events. That's why people were mentioning JS. If you've worked on frontend UI then you can't tell me you don't know what I'm talking about. (And yes, I know it can be done with just CSS instead of moving an absolutely-positioned header with JS in scroll events. Tell that to the websites that do it, not to me.)