Improvements to the Preface
Improved logo and favicon
Make code blocks white-space nowrap so that they're always on one line (but make pre>code blocks inherit the white-space from the pre)
Add new meta section styling
New box model sketch
Replace the box model PNG with an SVG exported from the new box model sketch
Add a meta section in the first chapter explaining that css properties can be clicked for contextual information
Improvements to chapter 1 for clarity/readability