What's the best way to instruct org-mode to embed all the css from my stylesheet into a single HTML file, rather than including a link to it as it does by default?
I faced this problem recently and none of the suggestions/answers worked for me. I finally found a solution in this link, which is to write your own function as follows and put it in you .emacs or init.el file.
(defun my-org-inline-css-hook (exporter)
"Insert custom inline css"
(when (eq exporter 'html)
(let* ((dir (ignore-errors (file-name-directory (buffer-file-name))))
(path (concat dir "style.css"))
(homestyle (or (null dir) (null (file-exists-p path))))
(final (if homestyle "~/.emacs.d/org-style.css" path))) ;; <- set your own style file path
(setq org-html-head-include-default-style nil)
(setq org-html-head (concat
"<style type=\"text/css\">\n"
"<!--/*--><![CDATA[/*><!--*/\n"
(with-temp-buffer
(insert-file-contents final)
(buffer-string))
"/*]]>*/-->\n"
"</style>\n")))))
(add-hook 'org-export-before-processing-hook 'my-org-inline-css-hook)