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Z-Index

CSS Z-Index

A property controlling the stacking order of overlapping positioned elements on the z-axis.

Détail technique

CSS z-index is part of the CSS specification maintained by the W3C CSS Working Group. Browser rendering engines (Blink, WebKit, Gecko) implement the specification through their layout and paint pipeline stages. Understanding the rendering pipeline — Style → Layout → Paint → Composite — is key to writing performant CSS. Properties that trigger layout recalculation (width, height, margin) are more expensive than those that only trigger compositing (transform, opacity).

Exemple

```css
/* Example: Z-Index */
.element {
  /* Apply z index to this element */
  display: block;
  margin: 0 auto;
}
```

Outils associés

Termes associés