How do you make an absolute positioned element honor the padding of its parent? I want an inner div to stretch across the width of its parent and to be positioned at the bottom of that parent, basically a footer. But the child has to honor the padding of the parent and it's not doing that. The child is pressed right up against the edge of the parent.
So I want this:
but I'm getting this:
<html>
<body>
<div style="background-color: blue; padding: 10px; position: relative; height: 100px;">
<div style="background-color: gray; position: absolute; left: 0px; right: 0px; bottom: 0px;">css sux</div>
</div>
</body>
</html>
I can make it happen with a margin around the inner div, but I'd prefer not to have to add that.
Best Answer
First, let's see why this is happening.
The reason is that, surprisingly, when a box has
position: absolute
its containing box is the parent's padding box (that is, the box around its padding). This is surprising because usually (that is, when using static or relative positioning) the containing box is the parent's content box.Here is the relevant part of the CSS specification:
The simplest approach—as suggested in Winter's answer—is to use
padding: inherit
on the absolutely positioneddiv
. It only works, though, if you don't want the absolutely positioneddiv
to have any additional padding of its own. I think the most general-purpose solutions (in that both elements can have their own independent padding) are:Add an extra relatively positioned
div
(with no padding) around the absolutely positioneddiv
. That newdiv
will respect the padding of its parent, and the absolutely positioneddiv
will then fill it.The downside, of course, is that you're messing with the HTML simply for presentational purposes.
Repeat the padding (or add to it) on the absolutely positioned element.
The downside here is that you have to repeat the values in your CSS, which is brittle if you're writing the CSS directly. However, if you're using a pre-processing tool like
SASS
orLESS
you can avoid that problem by using a variable. This is the method I personally use.