Introduction
Scroll down to see the progress bar fill as you move through the page. The progress is calculated as the percent of content scrolled and updated using requestAnimationFrame for smooth animations.
Section 1
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer ut ...
(Repeat multiple paragraphs for demo.)
Section 2
Donec mollis, arcu a convallis efficitur, tortor elit pharetra arcu, quis ...
Section 3
More content... (Use real article or documentation content in production.)