Text is limited to a single drop-shadowed font.

Style Mapping - Allows grouping of style-linked fonts to be treated as a single font.

The approach works best when limited to a single font of one size.

This allows a single font to represent two alphabetic scripts.

At the beginning the type consisted of the notehead, stem and staff which were combined into a single font.

Some twenty years ago a single font would have cost you around $4,500.

Nowadays a single font will cost, perhaps, $45 and it can be used on almost any make of typesetter.

Their use continued with early computers, which could only display a single font.

Compared to the Macintosh, AES provided a rather spartan look and the system shipped with a single monospaced font.

I agree with you, I don't have a Kindle but it does look to me like you're stuck with a single font (although with multiple sizes).