So I've been seeing this odd behavior where sometimes after going into italics and coming back to normal text, the font will suddenly be about 3 pts bigger. I spent hours wrestling with this and finally came to a solution. It might not be the BEST solution but it works for me and isn't terribly hard.
To be completely clear, I use Pages '09 on my macbook pro and export to RTF prior to importing to Calibre
1. Convert the book to the azw3 format and edit using the right click edit option in Calibre.
2. Go into the css file at the bottom of the left side of the editor and change the node ( .node, .node1, .node2, etc) definitions to use the same font size. There are a couple exceptions. A couple of them should remain larger because they are titles and such. You have to experiment a bit. Once you have the css how you like it, copy the contents and save it off somewhere
3. convert the azw3 to mobi using Calibre and it should all be good.
The catch to this is that I've noticed that sometimes the node definitions are different in different books. So you can't just dump the css in on the book wholesale. You'll have to repeat the process but this time you'll already know what you want your font sizes to be.
This solution isn't the best, but I'm a software guy so dealing with css is easy enough for me. l'm willing to field questions if you get stuck on this.
If anyone else faces this and has a better solution I'd love to hear it
