The article seems to focus on what is and isn't good to read. I'd say, don't focus on reading at all, focus on building. Decide to build something that'll need some CSS, and search and read and try things in pursuit of the goal of getting that thing working right. It's more interesting and easier to remember things that you've actually used, or at least tried and decided not to use, than to just read about 50 things that you might never use at all.
I've always found value in at least scanning some articles and books for general overview of what is possible. Many dev get to a point where they learn a method and abuse it. It's the method they know and have never been exposed to an alternative. They found something that solves the problem sorta so why go look for something else.
While reading a lot of articles and books gives you a wider view, you don't have to memorize but as the article says, know it exists.
