CSS Box Model in Blink: Architecture of Layout and Paint

The provided text describes the Blink rendering engine's implementation of the CSS box model, detailing how digital elements are structured, positioned, and rendered. It explains the transition from the layout tree, which mirrors the DOM, to the fragment tree, a modern system that handles complex scenarios like multi-column layouts and line wrapping. The source clarifies how various regions—content, padding, border, and margin—are calculated and how stacking contexts influence the final visual output. Additionally, it outlines the painting process, where fragments are converted into drawing commands and organized into layers for efficient GPU compositing. The text also highlights performance optimizations, such as layout containment and fragment caching, which ensure smooth browser experiences. Ultimately, these technical documents bridge the gap between abstract W3C specifications and the practical C++ architecture that powers Chrome's layout engine.