Splitting my pages into parts (eg. header and content), I can’t avoid placing links to external stylesheets within <body> tags.
I don’t want to place all styles in one big file or enclose all stylesheets within the <head> tag because page-specific stylesheets shouldn’t be loaded unnecessarily.
In this case, is it appropriate to place a stylesheet within the <body> tag? Is there a better alternative?
you shouldn’t place styles within the body tag, but assuming you’re using a server side script (PHP?) to link both header and content, why not write your own class to generate your pages; you could have a method that add styles to the header, and one that outputs the page for instance.