One of the things that makes it hard to ‘get’ the hierarchy or specificity of CSS that was written by someone else is that there are so many different ways to write CSS. I sometimes compare it to the art of writing prose. Not everyone who has learned to spell and understands the basics of grammar, can write like Stephen King or Gabriel Garcia Marquez or William Shakespeare.
Even if you haven’t read those authors, you can quickly appreciate that Marquez was a master at magic realism, which is quite different from the science fiction and horror that Stephen King is famous for in books like Carrie and The Shining. To further complicate matters, the way many of us write CSS has changed over time. William Shakespeare is still considered a master, but few teachers would recommend you write the way he did anymore. Similarly, even well-written CSS, if it’s a few years old, may read like Old English today.
ThemeForest and Woo Themes are considered some of the better sources for templates and WordPress themes, but as soon as you find yourself reviewing someone else’s CSS, you have to take into consideration that every author has their own style, that there are many ways to create the same design effects with CSS, and that if you really want to write the cleanest, best code possible, you’ll spend hours on the details — in much the way a great writer can spend an afternoon looking for just the write word.
The more you learn about CSS, the better you’ll get at writing (and reading) it, but at the end of the day, some of the differences in style sheets come down to, well, style.
You can learn more about the basics from my CSS training videos.