I agree. I bought the "Bible" Bringhurst's Elements of Typographic Style and while I found it very interesting, I wasn't that convinced it applied to the web.
Vertical rhythm, which is mentioned in the book, is mentioned because when you print on paper pages you want the lines to overlap on the front and back of the page (so they don't bleed through making it harder to read), and so when the one page right next to the other one aren't misaligned.
I don't really think those apply to the web so much.
That said, it's all too easy in CSS to end up with wonky padding/margin if you don't have a consistent rule about whether to apply it to the top or bottom and by how much. So it's possible to end up with headlines up against body text or big gaps before the first paragraph, etc. I think that's worth fixing.
> if you don't have a consistent rule about whether to apply it to the top or bottom and by how much.
I recommend to use only top margins and to apply them to every element which isn't the first child (`whatever:not(:first-child)`).
This way there is no extraneous spacing at the very top or very bottom, which means the only spacing around the content is the padding of the container.
It's the same idea as the "lobotomized owl" selector (`* + *`). It's just more explicit.
Vertical rhythm, which is mentioned in the book, is mentioned because when you print on paper pages you want the lines to overlap on the front and back of the page (so they don't bleed through making it harder to read), and so when the one page right next to the other one aren't misaligned.
I don't really think those apply to the web so much.
That said, it's all too easy in CSS to end up with wonky padding/margin if you don't have a consistent rule about whether to apply it to the top or bottom and by how much. So it's possible to end up with headlines up against body text or big gaps before the first paragraph, etc. I think that's worth fixing.