How Do I Effectively Superimpose Backgrounds on HTML's `` and `` Elements?

Applying Backgrounds to and

In HTML layouts, applying a background to both and elements can yield unexpected results. This article examines the expected behavior and provides solutions for superimposing multiple backgrounds.

Background Propagation in Standards Mode:

In standards mode, does not automatically take up the viewport height, even though it may appear to do so with a background. If no background is set for , it inherits the background from . However, if you explicitly specify a background for , that background extends to cover the entire canvas, including .

Single Element Superimposition:

To superimpose two background images over a background color on a single element, such as or , you can use the background or background-color properties. For example:

body {
    background: #ddd url(background.png) center top no-repeat;
}

Superimposing Background Images on Multiple Elements:

To combine multiple background images using multiple elements, you can apply different background settings to and . For example, set a background image to and another to that is intended to overlay it. Ensure that and are sized correctly for full-screen height.

Multi-Layered Backgrounds in CSS3:

In CSS3, you can declare multiple background values in a single property, eliminating the need for multiple elements. For example:

body {
    background: url(background2.png) center top no-repeat, 
                #ddd url(background1.png) repeat;
}

Note that only the bottommost layer in a multi-layered background can have a background color.

Support for Older Browsers:

For browsers older than CSS3, you must use the multiple element method to superimpose backgrounds. Ensure that and have the correct heights and margins.

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