Re: Image bleeds and page backgroud

Hello,

my observation is, that simply CSS support in several EPUB viewers, even in 
some extensions for browsers, is completely borked, because they fail to care 
about the CSS cascade/priorities concerning user-agent stylesheet, author 
stylesheets, user stylesheets.
Even it one sets major properties with important! still they present a 
nonsense mixture of own rules and author rules.
Additionally many have not an option for the audience at all to switch between 
alternative author stylesheets, respectively to switch off the interpretation 
of author stylesheets.

This results sometimes in accessibility problems for the audience, for 
example, if the author stylesheets defines light text on dark background as 
default because it fits pretty good to the content, but the user-agent 
stylesheet with wrong priorities overwrites only the dark background with 
white - suddenly the audience has light gray text on white background, just 
because the viewer fails to manages different stylesheets according to the CSS 
recommendation.
Because the option is missing to simply switch to another author stylesheet, 
the book becomes unreadable with such a borked reader.
But I have seen as well, that there are viewers, which ignore the indication 
of an alternative stylesheet and mix different alternative author stylesheets 
and the user-agent stylesheet in an arbitrary way, with funny results as well.

Therefore typically this seems to be more a problem of bugs in viewers, than a 
problem of books or EPUB itself ...
An it is not limited to EPUB viewers, the proprietary Amazon/Kindle viewers 
have similar bugs, if applied to books converted with kindlegen from EPUB to 
the proprietary Amazon formats (one needs to do this conversion, because such 
Amazon/Kindle viewers fail to present EPUBs at all).


Olaf

Received on Wednesday, 7 June 2017 12:53:30 UTC