Cathy, this is a great and very informative article, and thanks for it. I do think you failed to address what in my experience is the most frustrating aspect of CSS: that in almost all real cases, you don’t have full control over the CSS. Instead, you have to work with (and often against) other CSS that is imposed on you — from Bootstrap, Foundation, video players, etc. What it means in practice is that instead of simply creating an effective stylesheet, most of the time you’re figuring how to override what someone else’s stylesheet is doing, which isn’t appropriate to your content. That is the only reason I ever use !important — but in more cases than I like to think about, it’s the only way I’ve found to get what I want.