This book isn't anti-trends. But trends are all in the 5%. The 95% is boring and conventional. The 95% works for almost every document ever produced, and a whole lot of UI stuff too.
Trends are unconventional by definition. So there’s no reason to remember conventions to represent them.
The mistake people make over and over with trends is not future-proofing the work. Look no further than the mass internet graveyard of Flash.
The full-page fancy whatever-you're-doing, and that cool trick with SVGs might not work next month. Browsers are always optimizing something away, and bleeding edge fancy design stuff is always the first to be hit.
Worse is that it won’t fully break. It’ll just stutter or just look a little off. It’s sort of like tech debt. Optimization debt? Framerate debt? Whatever it’s called, you’ll probably never notice. That’s the worst part.
CASS is anti-trends. Or at least it aims to be as untrendy as possible, using standards that will endure and make sense even after CSS gains sentience and begins writing itself.
Trends take a lot of time and energy. That’s fine. They’re usually worth it. Use CASS to free up that time and energy, not as a source of new trends itself.
The Gumroad version contains a secret chapter that spills the dirt on CSS preprocessors, a tech CASS no longer uses.