HTML and CSS Reference
The first part of your toolset for working with CSS3 will be clean, semantic HTML,
also referred to as POSH (plain old semantic HTML). Not only is it advantageous
in many ways (e.g., better for search engine optimization, more accessible, easier
coding and maintenance), but it is essential for success when you start applying
advanced CSS techniques to your content. Trying to work out a system for using
advanced selectors to style copy or using multiple animations in a sane fashion is
more di cult if all you have to play with is horrible, old-fashioned spaghetti code
(to see an example of horrible spaghetti code, look at the source of pretty much
any CMS or Wiki page).
And because one of this topic's goals is to provide a forward-facing approach
to web design, you'll use HTML5 for all the markup in this topic.
WHY USE HTML5?
Before jumping into HTML5, let's consider HTML 4 for a minute. You'll probably
agree that it does a pretty good job of marking up static documents that you can
link between. This was the job it was originally written for. However, technology
never stands still, and many developers quickly decided that they weren't happy
just creating static documents. They wanted to start creating more dynamic sites
that behaved like applications, and for such tasks, HTML 4 was missing a lot of
native functionality. To implement video, animated graphics, and complicated form
controls, developers turned to proprietary technologies like Flash, or complicated,
functionality with open standards.