But I have a question about this template... it places the content first and then absolutely positions the header later above the content. The template info says this is better for accessibility and SEO. My question: is this a better practice than just placing the header first, content next, footer last? Does it really help accessibility and SEO that much to do this?
I designed that layout as a lot of people have requested it that way.
It is generally accepted (by peole more knowledgable than me) that the sooner the search engine sees good content then the better the rankings are likely to be.
Results do seem to show that this type of layout fares better than the standard approach.
However I'm of the opinion that you should design the site for people first and search engines second. If it makes more sense to you to structure your pages in the normal flow then do it that way but just be aware that your rankings may be a little lower.
As for accessibility it is better for screenreaders to read the content first rather than trawl through the header then all the navigation links before it arrives at the content. It has to then do this on every page.
(However a few well placed skip links could help avoid this anyway.)
It's up to you just put the header first if you want the layout is easy enough to change
Because the header is absolutely positioned then we need to allow space for it. The only way that can be achieved is to have a fixed height on the header and hide any overflow.
This is fine for banners and headings but if you wanted a fluid height for text that maybe comes from a cms (database etc) and you didn't know the height, then the header would need to be in the flow and come first in the html.