What is page_styles.css for?

[enuddleyarbl]

I'm assuming the various forms of page_styles.css I'm seeing (page_styles.css, page_styles1.css and page_styles3.css) in my epubs are there from Calibre's conversion process since they're present in every file. Purely out of curiosity, I'm wondering why they're their at all. Invariably, all that's in those files is:

@page { margin-top: 0; margin-left: 0; margin-right: 0; margin-bottom: 0; }

and that same bit of styling is also right at the top of stylesheet.css (which is, in general, where all the actual styling information is).

[theducks]

Sort of what it says overall PAGE

You are not limited to a single style sheet in a book.
Different sections may have different stylesheets

Pagestyles is the common bit. It may include @fonts

[JSWolf]

What I do is combine the CSS. I cannot stand multiple CSS files. An omnibus can be really bad in that regard as each book can have it's own CSS. That means each book in the omnibus could be formatted differently instead of done correctly with the same formatting (where possible) for each book.

[theducks]

Originally Posted by JSWolf

What I do is combine the CSS. I cannot stand multiple CSS files. An omnibus can be really bad in that regard as each book can have it's own CSS. That means each book in the omnibus could be formatted differently instead of done correctly with the same formatting (where possible) for each book.

That is not incorrectly, that is Quick-dirty & LAZY.

Rule #1: If it works... SHIP IT!

[Karellen]

Originally Posted by JSWolf

What I do is combine the CSS. I cannot stand multiple CSS files. An omnibus can be really bad in that regard as each book can have it's own CSS. That means each book in the omnibus could be formatted differently instead of done correctly with the same formatting (where possible) for each book.

Yes, I do the same. I delete the multiple css files then replace the css code in the remainin file with my css code. Then I adjust the html tags in the book to use the new css code.
(Don't forget to relink the new stylesheet which also clears out the redundant entries)

I assume that multiple css files are for human readability, not machine readability.

[kovidgoyal]

page_styles.css contain @page and @font-face rules. These cannot be applied with selectors therefore they cannot be in a common stylesheet, since different html files might need different values for them. THerefore there is one page_styles.css for every individual HTML file that needs different values for page margins, embedded fonts, etc.

[Karellen]

Originally Posted by kovidgoyal

since different html files might need different values for them.

Can I read that as... if I have no need to apply different page_styles.css to different html files, is it acceptable to not use a page_styles.css and combine it into the general stylesheet.css?

[kovidgoyal]

calibre conversion already only uses different page_styles.css files if they are actually needed.

[enuddleyarbl]

The odd thing is that I've never seen anything in those page_styles.css files except an @page with all margins 0. Lately, I've been working on reformatting my copies of Rex Stout's "Nero Wolfe" series. Those books contained 2-3 page_styles[n].css files that were always the same (I assume I must have done multiple conversions on them over the years to cause that). Since each file also contained stylesheet.css with all the actual formatting, I just removed the links to the page_styles versions and deleted those files.

EDIT: I think I've figured out what's happened with these. One of the first things I do is use Modify ePub on my books and remove all embedded fonts. I'll bet those fonts were referenced in the page_styles.css file. Once the fonts were gone, the page_styles.css files were left with nothing but the zero-margin @page.