[akita328]

I've tried to search for this problem, but haven't been successful in finding solutions, so here I'm posting.

I have ebooks downloaded from Internet Archive. but there are many errors in the IA epub, so I've been using sigil to clean up the errors and format it, then use calibre to convert epub to mobi, load it up into my Kindle and read it.

Conversion works for the most part, but I have found out that italics style doesn't show up as italics in Kindle, even if it looks okay in all the ebook previewers (except Kindle Previewer. it also fails to show italics).

I have found that if the word is using the following code, the italics shows up in all the previewers correctly, including kindle (this is what Sigil will embed when I convert words into italics while in html mode). simple html italics command:

<i>word in italics</i>

however if it's in this following form, the italics shows up on Sigil previewer, Calibre ebook reader, etc., but when converted to mobi and read through Kindle or Kindle Previewer, the italics do not show up (this is what Sigil will embed when I convert words into italics while in Preview mode/WYSIWYG interface):

<span style="font-style: italic;">word in italics</span>

As far as I can figure out, the format above is correct. so I assume This must be some vintage compatibility issue when converting to mobi that Kindle doesn't recognize? or is there some Calibre setting that I need to turn on for mobi conversion to correclty interpret the <span style > italics formatting?

how do I make the <span style="font-style: italic;">word </span> show up as italics when converting the epub to mobi to read in Kindle?

in other books where I converted .azw to epub, then edit and encode back to mobi, kindle seem to display italics using the <span style..> ok. but that conversion has a lot of calibre-specific style sheet stuff I don't quite understand.

can someone help me understand what I'm doing wrong?
..and yes. I understand basic html coding. but am a newbie.