Fluid CSS: floating column with max-width and overflow
I'm using a fluid layout in the new theme that I'm working on for my blog. I often blog about code and include <pre> blocks within the posts. The float: left column for the content area has a max-width so that the column stops at a certain maximum width and can also be shrunk:
+----------+ +------+
| text | | text |
| | | |
| | | |
| | | |
| | | |
| | | |
+----------+ +------+
max shrunk
What I want is for the <pre> elements to be wider than the text column so that I can fit 80-character-wrapped code without horizontal scroll bars. But I want the <pre> elements to overflow from the content area, without affecting its fluidity:
+----------+ +------+
| text | | text |
| | | |
+----------+--+ +------+------+
| code | | code |
+----------+--+ +------+------+
| | | |
+----------+ +------+
max shrunk
But, max-width stops being fluid once I insert the overhanging <pre> in there: the width of the column remains at the specified max-width even when I shrink the browser beyond that width.
I've reproduced the issue with this bare-minimum scenario:
<div style="float: left; max-width: 460px; border: 1px solid red">
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit</p>
<pre style="max-width: 700px; border: 1px solid blue">
function foo() {
// Lorem ipsum dolor sit amet, consectetur adipisicing elit
}
</pre>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit</p>
</div>
I noticed that doing either of the following brings back the fluidity:
- Remove the
<pre>(doh...) - Remove the
float: left
The workaround I'm currently using is to insert the <pre> elements into "breaks" in the post column, so that the widths of the post segments and the <pre> segments are managed mutually exclusively:
+----------+ +------+
| text | | text |
+----------+ +------+
+-------------+ +-------------+
| code | | code |
+-------------+ +-------------+
+----------+ +------+
+----------+ +------+
max shrunk
But this forces me to insert additional closing and opening <div> elements into the post markup which I'd rather keep semantically pristine.
Admittedly, I don't have a full grasp of how the box model works with floats with overflowing content, so I don't understand why the combination of float: left on the container and the <pre> inside it cripple the max-width of the container.
I'm observing the same problem on Firefox/Chrome/Safari/Opera. IE6 (the crazy one) seems happy all the time.
This also doesn't seem dependent on quirks/standards mode.
Update
I've done further testing to observe that max-width seems to get ignored when the element has a float: left. I glanced at the W3C box model chapter but couldn't immediately see an explicit mention of this behaviour. Any pointers?
Answer
Set margin-right: -240px; float: left; on the <pre> element to make it occupy as less horizontal space as possible and at the same time may overflow the parent <div> element with 240px. Remember to make sure that the <p> elements clears floating elements on both sides (clear: both). Complete example below:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
"http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<title>Solution</title>
</head>
<body>
<div style="float: left; background-color: cyan; max-width: 460px;">
<p style="background-color: magenta; clear: both;">
Lorem ipsum dolor sit amet, consectetur adipisicing elit.
Lorem ipsum dolor sit amet, consectetur adipisicing elit.
Lorem ipsum dolor sit amet, consectetur adipisicing elit.
</p>
<pre style="float: left; max-width: 700px;
background-color: yellow; margin-right: -240px;">
function foo() {
// Lorem ipsum dolor sit amet, consectetur adipisicing elit
}
</pre>
<p style="background-color: magenta; clear: both;">
Lorem ipsum dolor sit amet, consectetur adipisicing elit.
Lorem ipsum dolor sit amet, consectetur adipisicing elit.
Lorem ipsum dolor sit amet, consectetur adipisicing elit.
</p>
</div>
</body>
</html>