Lower Alpha Bullet List Not Working For Mobi

I am converting a regular .html file to .epub, .mobi, and .pdf and am having difficulty getting a lower alpha bullet list to display as such. It shows fine in .epub and .pdf but not .mobi file, not sure why.

This is what I am using:

<ol style="list-style-type: lower-alpha;"> (Wordpress uses)

Before that I was using this which did not work for any file format:

<ol type="a"> (Dreamweaver uses)

Any suggestions why .mobi won't render it as lower-alpha but the other two file formats do? Thanks!