Feature 423 block design & features
On large screens the block pins a two-column layout to the viewport while the visitor scrolls through a tall track. The left column holds the heading and a numbered chapter list, and the right column shows a framed product screenshot.
As the visitor scrolls, the active chapter moves down the list. It highlights its number and title, slides open its description and key points, and the screenshot on the right crossfades to match. A thin progress rail under the screenshot counts through the chapters, and clicking any chapter scrolls straight to it.
Each screenshot has a light and a dark variant, so the product imagery follows the site theme. The scroll handler is throttled with requestAnimationFrame and cleaned up on unmount.
Below the large breakpoint the sticky track is replaced by a plain stacked list, with each chapter's number, title, description and screenshot in sequence.