To your first question: For me, yes. Although, If I’m going to use it in multiple places with that same style, I’d find the best way to declare it once (like in a React component). Generally I much prefer to keep the style close to the element it’s styling, and I’d rather it be done declaratively rather than native CSS with polyfills. CSS is such a core part of appearance and behavior that building and debugging structures and style together is much more effective.