Several members at Webmaster World have asked if there was a method to assign 100% height to <div>'s used as left and/or right navigation menus. In some cases, members also wished to assign background-images to their div's that would always display at 100% of the resized browser window.
Most attempts to accomplish this were made by assigning the property and value: div{height:100%} - this alone will not work. The reason is that without a parent defined height, the div{height:100%;} has nothing to factor 100% percent of, and will default to a value of div{height:auto;} - auto is an "as needed value" which is governed by the actual content, so that the div{height:100%} will only extend as far as the content demands.
The solution to the problem is found by assigning a height value to the parent container, in this case, the body element. Writing your body stlye to include height 100% supplies the needed value.
body {
margin:0;
padding:0;
height:100%;
}
Now when height:100%; is applied to divs (or other elements) contained withing the body, the height percentage has a containing (body) value to work with.
The following example is a three column, liquid layout with 100% height assigned to both flanking divs. Background images can be assigned to these divs and will render at 100% of the window height.
Either copy-and-paste the following code into a new file, or click here to see a ready-made example.
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//Dtd XHTML 1.1//EN"
"http://www.w3.org/tr/xhtml11/Dtd/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" >
<head>
<title>One Hundred Percent Height Divs</title>
<style type="text/css" media="screen">
body {
margin:0;
padding:0;
height:100%; /* this is the key! */
}
#left {
position:absolute;
left:0;
top:0;
padding:0;
width:200px;
height:100%; /* works only if parent container is assigned a height value */
color:#333;
background:#eaeaea;
border:1px solid #333;
}
.content {
margin-left:220px;
margin-right:220px;
margin-bottom:20px;
color:#333;
background:#ffc;
border:1px solid #333;
padding:0 10px;
}
#right {
position:absolute;
right:0;
top:0;
padding:0;
width:200px;
height:100%; /* works only if parent container is assigned a height value */
color:#333;
background:#eaeaea;
border:1px solid #333;
}
#left p {
padding:0 10px;
}
#right p {
padding:0 10px;
}
p.top {
margin-top:20px;
}
</style>
</head>
<body>
<div id="left">
<p class="top">This design uses a defined body height of 100% which allows setting the contained left and right divs at 100% height.</p>
<p>This design uses a defined body height of 100% which allows setting the contained left and right divs at 100% height.</p>
<p>This design uses a defined body height of 100% which allows setting the contained left and right divs at 100% height.</p>
</div>
<div class="content">
<p>This design uses a defined body height which of 100% allows setting the contained left and right divs at 100% height.</p>
</div>
<div class="content">
<p>This design uses a defined body height which of 100% allows setting the contained left and right divs at 100% height.</p>
</div>
<div class="content">
<p>This design uses a defined body height which of 100% allows setting the contained left and right divs at 100% height.</p>
</div>
<div id="right">
<p class="top">To solve an inheritance issue displayed in div #right as rendered in Opera, class p.top using margin-top:20; is applied to the first paragraph of each outer divs.</p>
<p>This design uses a defined body height which of 100% allows setting the contained left and right divs at 100% height.</p>
<p>This design uses a defined body height which of 100% allows setting the contained left and right divs at 100% height.</p>
</div>
</body>
</html>
Tiling backgrounds may also be deployed:
#right {
position:absolute;
right:0;
top:0;
padding:0;
width:200px;
height:100%; /* works only parent container is assigned a height value */
color:#333;
background:url(images/mytile.gif) repeat;
border:1px solid #333;
}
A three column liquid layout was used for demonstration purposes, the 100% height can be applied as required.
The above three column layout will not display properly in Netscape 4.x because of the position:absolute; right:0; styles of the div #right. Remember to protect Netscape 4 from styles it cannot understand by using the @import rule.
The above has been tested in Opera6, IE6, and Mozilla 1.1 - it should work in most modern browsers.
Have fun!
XHTML + CSS + WebStandards = FREEDOM!
- papabaer ;)
################################
If you put that xml declaration under the Doctype it will still validate and won't trigger IE6's 'quirks' mode? The design may not suffer from being in 'quirks' mode but it's a point worth noting.
Nick
################################
Works okay in IE5 (but not konqueror). A passable workaround for that naughty little NS4 fella.... dump all the styles in a sheet but change the #right div to this:
#right { float: right; position: absolute; top: 0; padding:0; width:200px; height:100%; /* works only if parent container is assigned a height value */ color:#333; background:#eaeaea; border:1px solid #333; }
then @import the original #right and everybody's happy
Nick