KoboTouch driver extra CSS in calibre 8

[JSWolf]

Would it be possible to modify the extra CSS in the KoboTouch driver for calibre 8 to allow us to have different CSS based on ePub or KePub? Thanks.

[jackie_w]

With a bit of creativity, you can (sort of) do this already using the existing single override file, kobo_extra.css.

For example, by taking advantage of the "special Kobo <div>s" which have traditionally been injected during the on-the-fly epub --> kepub transformation:

/* Put all your epub-specific CSS rules first */

div#book-columns > div#book-inner {
    /* Put all your kepub-specific CSS rules here */
}

The epub will ignore the rules in the bottom half because it doesn't contain the special Kobo <div>s . The kepub won't ignore the rules in the top half but the bottom half rules come later in the CSS file so can override the rules in the top half if they conflict.

How well it works may depend on what kind of CSS differences you want for epub vs. kepub.

[JSWolf]

Originally Posted by jackie_w

With a bit of creativity, you can (sort of) do this already using the existing single override file, kobo_extra.css.

For example, by taking advantage of the "special Kobo <div>s" which have traditionally been injected during the on-the-fly epub --> kepub transformation:

/* Put all your epub-specific CSS rules first */

div#book-columns > div#book-inner {
    /* Put all your kepub-specific CSS rules here */
}

The epub will ignore the rules in the bottom half because it doesn't contain the special Kobo <div>s . The kepub won't ignore the rules in the top half but the bottom half rules come later in the CSS file so can override the rules in the top half if they conflict.

How well it works may depend on what kind of CSS differences you want for epub vs. kepub.

Given the state of the patches on the current firmware, the idea was to use the extra CSS to just add CSS to KePub to make the font sizes the same or similar to ePub.

[jackie_w]

Originally Posted by JSWolf

Given the state of the patches on the current firmware, the idea was to use the extra CSS to just add CSS to KePub to make the font sizes the same or similar to ePub.

My suggestion above should work for that scenario.

I just tried the following in the kobo_extra.css file on my Clara 2E running fw4.38.23429 without patch Unify font sizes.

/* This will be ignored by epubs */
div#book-columns > div#book-inner {
    font-size: 1.85em;
    }

It works OK for me. You may need to fine-tune the 1.85em value to suit yourself.

ETA: Of course if patch Unify font sizes resurrects itself in the next firmware then you'd need to resend all your kepubs to remove the font-size hack.

[npr]

This is what I use to add css to kepub's and be ignored by epubs:

/* Improve kepubs
word spacing and letter spacing */

#book-columns #book-inner
{
word-spacing: -0.055em;
letter-spacing: -0.005em;
}