Update:
I cannot get the previewer to accept the
@media [whatever] {} syntax inside a css context, only on devices. The previewer accepts
<style ... media="amzn-kf8 and whatever"> though.
The previewer recognizes "
amzn-kf8 and (width:758px)" as applying to the paperwhite, but not "
(device-width:758px)". According to
this blog,
device-width etc will refer to the computer screen the previewer is run on.
I have not succeeded in finding a width value for the previewer fire emulation mode.