The Zen theme has some of the attributes we're looking for in our final design and is pure CSS. The theme also has a useful structure for tutorial purposes and is well commented. Accordingly, we're going to start with Zen and modify it until we reach our final goal, that is, a new theme we will name "Tao".
Note
You can download a copy of the Zen theme at http://drupal.org/project/zen. Note, however, that the Zen theme is under active development and as a result, the version you download today may not be the same as the one used in the examples in this text.
Any time you set off down the path of modifying an existing theme to fit your needs, you need to spend some time planning before you start modifying code. The idea here is simple: a little time spent up front pays off big-time in savings later on.
A dissertation on site planning and usability is beyond the scope of this book, so for our purposes let us focus on defining goals and on satisfying a specific wish...