Project 2.9 CSS Type and Structures

Here is an example of how to use CSS to style the gropius_7.html web page.
I tried to:
1) Limit the amount of coding
2) Keep the coding simple
3) Have the result look good.
The margin:0 auto to center the main element and the width:100%; max-width:800px; are more advanced techniques, but I felt were important here; I don't like text that extends too far. Works for Wikipedia but doesn't work for me.