Re: [css3-page] Flexbox or table algorithm for page-margin box layout

Why not use a new position value, let's say page-area, with flexbox?

Håkon's example could be expressed like this:
<div class="margin-box"><div class="pagenum left"></div><div
class="title"></div><div class="pagenum right"></div></div>
.margin-box { position:page-area; left:0; right:0; bottom: -2%;
display:flex; justify-content:center; }
.pagenum { content: counter(page); flex:none; }
.title { content: string(chapter); flex:1 0 auto; text-align:center; }
@page :left .pagenum.right { visibility:hidden; }
@page :right .pagenum.left { visibility:hidden; }

This is actually better than what's currently in the css3-page spec, IMHO,
because instead of allowing the title and page number to overlap, the page
number would be pushed out into the left or right margin.

The only tricky thing I've done here is to allow :left and :right selectors
to style content inside the margin box element. We wouldn't want to allow
them to style content that's not inside a position:page-area or
position:fixed container. (BTW the only difference between
position:page-area and position:fixed is that the former isn't clipped to
the page area.)

Rob
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