[kapowaz]

> what I determined is that there's a new definition of what "semantic" means in front-end architecture. Semantic doesn't just describe the content anymore, it describes the function as well. So using classes like "module-box" or whatever is perfectly fine.

Semantics describes a thing, but classes like ‘module-box’ don't convey any meaning beyond presentation. If you think that ‘module-box’ is semantic, then I have a whole bunch of classnames based on colours to sell you…

> the "separation of concerns" was a good principle to use when the web was a bunch of documents meant to provide content. It isn't that way anymore.

The virtues of this approach have very little to do with the web; it's a concept that pre-dates it, so it's hard to justify it having been invalidated simply by advances in web technology. Besides, a web ‘application’ is equally composed of semantic components just as much as a document is; part of the reason HTML5 came about was to reflect the kind of elements used in modern web pages.

> Using selectors like that (aside from being slow performing) completely tie the markup to the presentation. Hell, if all you did was update the list to an ordered list instead of an unordered one you'd have to update the CSS as well.

This suggests that your workflow starts with CSS and you then build markup to fit it, which his sounds completely backwards to how I approach things. You don't tie your markup to how it is presented: you declare how you want to present the markup your app is built upon. Also, if you change the markup to something with a completely different meaning (an ordered list is meant to have a different purpose than an unordered one) then of course it follows that you'd have to update the CSS, although there's no reason why those changes need be onerous or difficult.

The whole selector performance debate is old and dead, by the way: http://calendar.perfplanet.com/2011/css-selector-performance....

> If you're concerned about the discoverability of the code to a new developer, DOCUMENT IT. Create a UI style guide that implements all of the major UI components and have the developer reference the style guide.

A style guide is a fine starting point regardless of how you want to approach your CSS, but documentation isn't the only way to aid discoverability of code. Selectors that communicate context and purpose can be very helpful for this too.