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Re: Block alignment problem clarification

From: L. David Baron <dbaron@fas.harvard.edu>
Date: Tue, 11 Apr 2000 12:13:11 -0400 (EDT)
Message-Id: <200004111613.MAA11035@is04.fas.harvard.edu>
To: graf@relhum.org, www-style@w3.org
On Mon, 10 Apr 2000 23:54:57 -0400 (EDT), Konstantin Riabitsev
(graf@relhum.org) wrote:
> 
> I have a question. Consider this structure:
> 
> <div id="parentDiv" style="text-align: center; width: 100%">
> <div id="childDiv" style="width: 50%">
> Div Contents here.
> </div>
> </div>
> 
> I've read the specification, and it says that when
> "text-align: center" is specified, all _inline_ content is aligned
> accordingly. However, it doesn't say what happens to block
> elements. Now, IE 5.5 would align "childDiv" in the middle of the
> page (it's half the parentDiv, so the alignment would be
> 25%-50%-25%). However, Mozilla-5 doesn't and I first noted that as a
> bug, but now that I think about it, I'm not sure.

It doesn't say anything about block elements in the definition of the
'text-align' property because 'text-align' has no effect on block level
elements.  The rules for block-level elements are defined in section
10.3.3 of CSS2 [1], which does not mention 'text-align'.  In other
words, the answer to your question is that the inner div should be on
the left 50% of the page, but its contents should be centered within
it.  Using 'auto' values for both margins can center a block-level
element.

-David

[1] http://www.w3.org/TR/REC-CSS2/visudet.html#q6

L. David Baron    Sophomore, Harvard (Physics)    dbaron@fas.harvard.edu
Links, SatPix, CSS, etc.     <URL: http://www.fas.harvard.edu/~dbaron/ >
WSP CSS AC                      <URL: http://www.webstandards.org/css/ >
Received on Tuesday, 11 April 2000 12:13:13 GMT

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