z-indexFor a positioned box, the z-index property specifies:

1. The stack level of the box in the current stacking context.
2. Whether the box establishes a stacking context.

]]>;]]>The stack level of the generated box in the current stacking context is 0. The box does not establish a new stacking context unless it is the root element.

]]>]]>This integer is the stack level of the generated box in the current stacking context. The box also establishes a new stacking context.

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