Introduction
In the previous chapter, you learned about forms, which allow you to work with user data in different ways. Data is important, of course – the modern world runs on it. It's not the only thing, however. For most people, all the data in the world is useless unless there's also a beautiful interface to access it with. Cascading Style Sheets (CSS) is the technology that will allow you to bring that interface to life on the web.
The power of CSS is its ability to change, sometimes radically, the appearance of a web page without updating the markup. This allows you to update the look and feel of a web page without you having any control at all over the content. This power expresses itself most commonly in themes, that is, CSS files that change the look and feel of a site or application and that can be applied easily. While some theming systems, like the ones in WordPress, allow and encourage dynamic changes to the markup, there's so much you can do...