One of the following web posts indicate the CSS code works for ePub2, EPUB3, and Kindle.
CSS hack:
body {
widows: 1;
orphans: 1;
margin-top: 0;
margin-right: 0;
margin-bottom: 0;
margin-left: 0;
text-align: justify;
-epub-hyphens: none;
-webkit-hyphens: none;
hyphens: none;
}
element {
adobe-hyphenate: none;
-webkit-hyphens: none;
-moz-hyphens: none;
-ms-hyphens: none;
-epub-hyphens: none;
hyphens: none;
}
Let us know if the CSS above will do it or get booted when the epub is loaded into KDP.
Sources:
mobileread
creativepro
dtperfect
Add on comments:
Correct, there's no way to get CSS into .kcb file; I presumed you had some midway software tool.
And directly setting your preferred 'hyphenation OFF' code in CSS is a 'hack' method. To clarify....
Prep tools people use: MSWord, OpenOffice [OO], LibreOffice [LO] writer, etc -- all are common tools for creating the base storyline or writing stage of a product intended for eBook destination.
From there its imported into Kindle Create (via .doc, docx, odf, etc) and saved as .kcb in there. If those are the only two software tools you use, then you are limited to not touching the CSS HTML.
Some refinements can be done in .kcb (images etc), some cannot (not CSS). We have not done any extensive editing inside a .kcb (other than adjusting the TOC) because everything we prep (CSS-HTML-JS) is done before it goes through that final KDP tool (as the mere final checkpoint before going live onto Amazon). We essentially proofed our product using epubcheck (and other means before going converting it in Kindle Create. Kindle Create software is as effective tool specifically designed to easily market product through that source (Amazon).
An earlier post described creating their base story in 'OO', the importing it into Calibre, adjusting some code there (if need), then saving it as an epub ready product, which is then uploaded into Kindle Create to be converted as the last step into .kcb and then going live (if all passed).
Free tools like Calibre, and Sigil are quite common (and fairly easy) to use (in epub creation) if you don't want to commit to higher priced software tools for epub making. Though its an external post, here are some comments that others spoke about the same issue:
MobileRead
Tools like Calibre/Sigil are worth that middle step (if you have the time to learn it). It allows that leeway to make those (hopefully) rare tweaks to the CSS/HTML that may be needed before converting it into .kcb at Kindle Create.
Even the KDP help pages speak plenty about CSS HTML code, and they presume that the person making the epub will have the software to access some of that code (if or when needed).
KDP help
Kindle Create is known for re-formatting the prepped CSS code (even we encounter it), and when you view it in .kcb you can sometimes get a surprise (for KDP can and may strip out certain CSS code) and re-format it their way.
I've also did a bit of web reading to see if we've overlooked any ideas for you, but there really aren't other options than to take the slower longer path through additional middle ground software.
That midway epub software (where you can make those types of adjustments to the CSS and HTML) is merely a choice to either have or have not (between the base raw writing) and the final Amazon KDP .kcb file to its live end product.
The more you want to tweak an epub (before it reaches Kindle Create .kcb terrain) the more you will need that midway software tool (like Calibre/Sigil/etc).
Or the rough road....learning the CSS HTML direct coding method.
Or...the costlier route of higher end epub creation software designed to cover all those CSS HTML tasks inside its own specialized software.
