# Z-Index

Set the stack order for an element.

**Widely available.** This feature is well established and works across many devices and browser versions.

Chrome 1 · Edge 12 · Firefox 3 · Safari 1

| Class | Properties | Value |
|-------|------------|-------|
| `zi:0` | z-index | `0` |
| `zi:10` | z-index | `10` |
| `zi:20` | z-index | `20` |
| `zi:30` | z-index | `30` |
| `zi:40` | z-index | `40` |
| `zi:50` | z-index | `50` |
| `zi:60` | z-index | `60` |
| `zi:70` | z-index | `70` |
| `zi:80` | z-index | `80` |
| `zi:90` | z-index | `90` |
| `zi:9999` | z-index | `9999` |
| `zi:auto` | z-index | `auto` |

## Variants

Prefix any class with a variant to apply it only under that condition. Variants stack, as in `@md:h:zi:60`.

### Breakpoints

Apply a class from a viewport width up. Each breakpoint covers its width & every width above it.

| Class | Applies |
|-------|---------|
| `@xs:zi:60` | From 32rem up. |
| `@sm:zi:60` | From 40rem up. |
| `@md:zi:60` | From 48rem up. |
| `@lg:zi:60` | From 64rem up. |
| `@xl:zi:60` | From 80rem up. |
| `@xxl:zi:60` | From 96rem up. |

### Containers

Apply a class from a container's width up, not the viewport's. Mark the parent with `ct:is` first.

| Class | Applies |
|-------|---------|
| `@c:xs:zi:60` | Container from 32rem up. |
| `@c:sm:zi:60` | Container from 40rem up. |
| `@c:md:zi:60` | Container from 48rem up. |
| `@c:lg:zi:60` | Container from 64rem up. |
| `@c:xl:zi:60` | Container from 80rem up. |
| `@c:xxl:zi:60` | Container from 96rem up. |

### Media

Apply a class when the device or the page matches a condition, or on the first frame an element renders.

| Class | Applies |
|-------|---------|
| `@pc:zi:60` | On a touch screen. |
| `@prm:zi:60` | With reduced motion on. |
| `@st:zi:60` | On the first frame. |

### States

Apply a class only while the element is in a state, such as hovered, focused or checked.

| Class | Applies |
|-------|---------|
| `h:zi:60` | On :hover. |
| `f:zi:60` | On :focus. |
| `fv:zi:60` | On :focus-visible. |
| `a:zi:60` | On :active. |
| `d:zi:60` | On :disabled. |
| `fc:zi:60` | On :first-child. |
| `c:zi:60` | On :checked. |
| `e:zi:60` | On :empty. |
| `fw:zi:60` | On :focus-within. |
| `i:zi:60` | On :invalid. |
| `in:zi:60` | On :indeterminate. |
| `lc:zi:60` | On :last-child. |
| `nc:zi:60` | On :nth-child. |
| `r:zi:60` | On :required. |
| `ro:zi:60` | On :read-only. |
| `v:zi:60` | On :valid. |

### Pseudo Elements

Style a part of the element rather than the element itself, such as its placeholder or the selected text.

| Class | Applies |
|-------|---------|
| `a::zi:60` | On ::after. |
| `b::zi:60` | On ::before. |
| `p::zi:60` | On ::placeholder. |
| `s::zi:60` | On ::selection. |

### Negative

Put a minus after the colon to negate a value.

| Class | Applies |
|-------|---------|
| `zi:-10` | A minus after the colon. |