Floating element dissapears behind background when container has position:relative - css

Question

I have boiled down my problem to a pretty simple single file with the CSS included in a <style> tag.
The problem is:
I have a floating right column with a transparent background to show some text and pictures. This works fine, as expected.
Now I want to position a "Site designed by.... " block just above the footer.
I want to use an absolute positioned div for this, which is positioned relative to the containing #content div, which must get the position:relative property to achieve this.
When I set this property, the floating right column disappears, and seems to be hidden behind the background image of the #content block.
I cannot find an explanation for this. A workaround would be to position it relative to the footer (in that case the #footer div would get the position:relative property).
But I just would like to understand what goes wrong here and why the floating column is hidden. See the links for the layouts without and with the relative positioned content div.
Understandably, in the case of no relative positioning, the text is positioned relative to the browser in the bottom left corner.
http://websites.drsklaus.nl/relativeproblem/index_withoutrelative.html
http://websites.drsklaus.nl/relativeproblem/index_withrelative.html

Answer 1

You were almost there! Heres a little help to finish it.
#main {
width: 1005px;
margin: 20px auto; /* shorthand margin for x and y axis */
border: solid black 1px;
/* Added background to main instead so it still covers the full background */
background-image: url('grey-repeating-background-4.jpg');
}
#content {
position: relative;
min-height: 500px;
/* made the padding here margin, made it slightly bigger to accomedate the right column */
margin: 5px 370px 5px 5px; /* Margin right should be as wide as the right column+extra space */
}
The reason for your right column to hide behind the content is that before you put position:relative; on it it is in normal flow, not 'positioned' and so z-index priority is really just by DOM order. Positioning it just made it a whole lot more important; obscuring the right column.