Gérard Talbot wrote:[color=blue]
> Gus Richter a écrit :
>[color=green]
>> Gérard Talbot wrote:
>>[color=darkred]
>>> Hello fellow colleagues,
>>>
>>> Can someone explain to me why, in this page
>>>
http://www.aplus.co.yu/css/z-pos/index4.php#content ,
>>> AP1 should not be in front of (overlapping) AP2 ?
>>>
>>> Recap:
>>> RP1 is relatively positioned block, with z-index:11
>>>
>>> AP1 is an absolutely positioned block, with z-index:10, nested inside
>>> RP1
>>>
>>> RP2 is relatively positioned block, with z-index: auto
>>>
>>> AP2 is an absolutely positioned block, with z-index:20, nested inside
>>> RP2
>>>
>>> -------
>>>
>>> In the second example where
>>> RP1 has z-index: 11
>>> AP1 has z-index: 1000
>>> RP2 has z-index: auto
>>> AP2 has z-index: 20
>>> I do not see/understand why AP1 shouldn't be in front of AP2.[/color]
>>
>>
>>
>> Because they're in a different "stacking context" - in a different
>> sub-stacking order.
>>
>>
http://www.w3.org/TR/CSS21/visuren.html#x36[/color]
>
>
> I still don't get it. RP1 has a greater stack level than RP2. So it
> should be in front of RP2. 11 is greater than 0.
>
> "Boxes with greater stack levels are always formatted in front of boxes
> with lower stack levels."
>
> Now, the sub-stack level shouldn't change that. 11.10 is still greater
> than 0.20.
> "For those with 'z-index: auto', treat the element as if it created a
> new stacking context, but any descendants which actually create a new
> stacking context should be considered part of the parent stacking
> context, not this new one."
>
http://www.w3.org/TR/CSS21/zindex.html#q2
>[/color]
I hope that I'm going to get it right this time!
Sorry, I mixed up the 1st and 2nd example in my deleted initial
response. Here is the way I see it in order of bottom to top, or back to
front for the first example:
RP2 z-index:auto or zero (does not establish a new local stacking
context.)
RP1 z-index:11 (current stacking context) z-index:0 (local stacking
context)
AP1 z-index:10 (local stacking
context)
AP2 z-index:20 (current stacking context)
--
Gus
Tough z-index questions 
