What's CSS? Learn It in 4 Hours - Companion Files
John Rouda - whatscss.com

capstone-start/
  Chapter 15's starting point: The Daily Grind home page as clean,
  semantic HTML with no styling at all (Figure 15.1), plus an empty
  style.css already linked. Open index.html in your browser and start
  typing Example 15.1 into style.css.

capstone-finished/
  The same page with the complete Chapter 15 stylesheet applied
  (Figure 15.2), for checking your work or exploring in DevTools.
  Chapters 16-18 exercises (outlines, reorganizing, custom properties,
  recipes) all continue from this file.
