Using writing-mode raises "Unknown Property name" warning

[chapkachapka]

The writing-mode property is defined in CSS Writing Modes level 3, which has been in Recommended status since December 2019.

When I run ebookmaker on a project containing:

span.vertical {writing-mode:vertical-lr;}

I get the following errors:

WARNING Property: Unknown Property name. [94:23: writing-mode]

WARNING:CSSUTILS:Property: Unknown Property name. [94:23: writing-mode]

and the writing-mode tag is not passed through to the epub3 file, even though the epub3 Overview states that epub3 "supports CSS styles that enable both horizontal and vertical layout and both left-to-right and right-to-left writing."

I have manually edited the ePub produced by ebookmaker to re-add the writing-mode property and tested with three ebook reading apps (ADE 4.5, Calibre, and Apple Books) and all recognise the writing-mode property and render the vertical text correctly.

[eshellman]

could you post a sample file please?

[chapkachapka]

I've uploaded a small project here:

https://github.com/chapkachapka/wmode

[eshellman]

Thanks! I'll be working on an ebookmaker release this week.