Quite new to writing and editing ebooks and I wondered something.
I know in webpages it's possible to produce alternate styling and content based on what the content is being viewed on. So CSS can style something differently for print than for screen and differently for mobile than for tablet or PC.
Is the same true in epub?
I'm thinking most specifically of cover images and other (potentially) colour content.
I'm painfully aware, due to being sight impaired, that some book covers which look great and are easy to look at or read in colour are less than optimal in black and white or are great as a full size cover but barely recognisable as a thumbnail.
Is it possible to code an epub so that a different cover image is shown on a black and white ereader than would be seen on a colour screen.
I'm asking not just as a user who needs acessibility but also as someone who would like to produce ebooks which are as acessible as possible.
The other route is going for high contrast low detail colour so that, monochrome or coloured and large scale or thumbnail, you always get something recognisable and readable. However this places more limitations on design options.
Of course I'm not even sure that thumbnails are a part of the epub or whether they're just generated from the main cover image by whatever software or device holds the ebook.
Any advice on this would be greatly appreciated.