title_body: Media queries to distinguish between Kindle e-inks vs non-e-inks
upvoted_answer: The preferred solution (and the one I use) is to create default css outside of the media query breakpoints, and then this css will apply to e-ink devices (which don't support media queries -- even the amzn-mobi one, to my knowledge)
  
  You should check the PDF of "Amazon Kindle Publishing Guidelines" on their website. Current version is 2015.4 
  
  I think your sample code is fine; my experience has been that it is unnecessary (and cumbersome) to use amzn-mobi in your media query. You can just use generic ones and you'll be fine. 
  
  My personal experience is that this breakpoint you listed is unnecessary: 
  
   amzn-kf8 and (device-aspect-ratio:1280/800) 
  
  
  I don't have all the devices to test with, but some things I have learned is: 
  
  
  Kindle app for android and Kindle Fire devices render things very
  similarly.
  Older e-ink devices also do an admirable job for limited hardware.
  The main thing you need to check is image size.  The trick is to use high
  quality images (1000px or 1500px) in the epub/mobi file and then let
  the Kindle website reduce its size accordingly. Don't try to figure
  out the algorithm Kindle uses for shrinking images. I used to waste
  a lot of brain cells on that. I actually posted my tips on formatting images for kindle devices here: https://kdp.amazon.com/community/thread.jspa?threadID=291039&amp;tstart=15
  Kindle for  Ipad 1 and the for latest Ipads and Ipad Minis are
  relatively similar for the purpose of testing (aside from screen
  dimensions obviously).