This is a book to deal with writing CSS for large-scale, rapidly changing web projects and applications.

This isn't actually a book about writing CSS, as in the stuff inside the curly braces. It's a book about the organisation and architecture of CSS; the parts outside the braces. It's the considerations that can be happily ignored on smaller projects but actually become the most difficult part of writing CSS in larger projects.

Here are some of the topics covered in the book:

- The problems of CSS at scale: specificity, the cascade and styles intrinsically tied to element structure.

- The shortfalls of conventional approaches to scaling CSS.

- The ECSS methodology and the problems it solves.

- How to develop consistent and enforceable selector naming conventions with ECSS.

- How to organise project structure to more easily isolate and decouple visual components.

- How to handle state changes in the DOM with ARIA or override selectors.

- How to apply ECSS to web applications and visual modules.

- Considerations of CSS tooling and processing: Sass/PostCSS and linting.

- Addressing the practicalities of using potentially problematic HTML elements.

- Addressing the notion of CSS selector speed with hard data and browser representative insight.