This extensive guide thoroughly explains the process of developing features for Blink, Chromium's rendering engine, focusing on HTML/CSS. It begins by highlighting the critical role of web standards (WHATWG for HTML and W3C for CSS) as the foundational blueprints for browser behavior. The text then details Blink's internal architecture, outlining the rendering pipeline from parsing HTML/CSS into DOM/CSSOM, through style computation and layout, to painting and compositing pixels on screen. Furthermore, it describes the structured "Intent" process within Chromium for proposing and shipping new web platform features, emphasizing the importance of prototyping, testing, and community engagement. Finally, the guide maps Blink's code structure within Chromium's multi-process architecture and equips developers with essential tools and techniques for building, testing, and debugging their contributions effectively.