CSS:z-index
From MDC
[edit] Summary
The z-index property specifies the z-order of an element and its descendants. When elements overlap, z-order determines which one covers the other. An element with a larger z-index generally covers an element with a lower one.
- Initial value:
auto - Applies to:
positioned elements - Inherited: no
- Media:
visual - Computed value: as specified
[edit] Syntax
z-index: auto | <integer> | inherit
[edit] Values
- auto
- The element is drawn at the same z-order as an element with
z-index: 0. It does not create a new stacking context. - <integer>
- The element is drawn at the z-order given. It also creates a new stacking context, which means that all of its descendants also draw at that z-index. This means that the z-indexes of descendants are not compared to the z-indexes of elements outside this element.
[edit] Examples
[edit] Notes
Negative z-index values are supported correctly starting in Gecko 1.9 / Firefox 3. Previous versions implemented the CSS 2 behavior, not the CSS 2.1 behavior that is compatible with other browsers.