I don't think it's absolute blasphemy to use #ids, but try to never use them. Think of it that way. I tend to use them only for #js-functionality hooks, which is also a good-practice to tell someone "don't freaking change this ID or you break the JS."
Tips from http://www.betterfrontend.com
There's no difference using that to
Psuedo example, those can be mix and matched with classes and IDS but doing so just complicates the selectors and the cascade.
There is of course exceptions and things that may just make total sense, but overall, it leads to complications. You don't gain any real benefits unless it's a JS hook for #id selector performance.
That's not very nice.
Thanks for the heads up. It should be fixed now. Clear cache the "hard" way if you have to.