No Css, only Html, ncx and opf files are there with an Images folder.
OK, let me tell you what I did.
1) installed kindleunpack clalibre plugin
2) unpacked and produced html file
3) viewing the HTML file in Calibre shows already extra white lines
4) I split the HTML in word, save it and convert to Mobi. White lines still there
Just tried to use kindlegen instead of calibre for conversion.. no difference
