[stevejohnson]

First, give this a read: http://practicaltypography.com/

I like your design. I just have a few nitpicks...

* Only center titles; don't center body text!

* Your body text should be 90 characters wide, max. The paragraph under the photo is much too wide.

* Spacing under titles seems too small to my eyes.

* Triangles as bullet points look a little odd (this is really subjective)

* The login button is in a bit of a weird place. Right-aligned is nice, but it looks misaligned vertically with the logo.

My take on this stylesheet would be...

    .headline { margin-top: 0; }
    .h1, h2, h3 { margin-top: 0.7em; margin-bottom: 0.7em; }

Remove text-center from any body copy. Use <ul> tags for lists.

Regardless of the above, your work looks great.

[mden]

Partially off topic, but page layouts like the one you linked to really come off as unnatural to me. Specifically the way the margin for annotations is used in the centering of the main content is distracting. It's like you are giving equal relevance to sporadic notes as to the main article. I'm surprised to see it in a typography book.