# Overlay

- Page: https://jiguang132.com/resources/mantine/docs/overlay
- Resource: Mantine Core (https://jiguang132.com/resources/mantine.md)
- All guides: https://jiguang132.com/resources/mantine/docs.md

Install: `npm install @mantine/core@9.7.1 @mantine/hooks@9.7.1`

## Version and compatibility

Pinned Mantine Core 9.7.1 requires React and React DOM `^19.2.0` and matching `@mantine/hooks@9.7.1`, from the installed npm package's peerDependencies. Do not force it into React 18 or another incompatible version. Explain upgrade impact and agree on a plan with the project owner; do not hide conflicts with --force/--legacy-peer-deps. The native Provider enables `theme.respectReducedMotion` and uses `forceColorScheme` for light/dark.

## Use case

Place a translucent layer over a region.

## Native props used by this example

These props are extracted from the local typechecked JSX and grouped by their owning native component. This is not an exhaustive prop list; see pinned source signatures and inheritance below.

| Component prop | Explanation |
| --- | --- |
| `Box.pos` | Mantine positioning style prop. |
| `Box.p` | Mantine padding style prop. |
| `Overlay.color` | Native color value or theme color key. |
| `Overlay.backgroundOpacity` | Background alpha, not the opacity of child content. |

## Interaction and state checks

Current scenarios: Default. Check actual behavior after selecting supported disabled/error/read-only scenarios; components without those native states do not receive invented universal props. Verify keyboard focus and exits, then connect changed values through the native callback signature.

## Business integration boundary

Demo content/state is local, without server persistence, authorization or fetching. A static display component is not a completed business workflow.

## Host setup

Install pinned @mantine/core and @mantine/hooks, import @mantine/core/styles.css at the entry and use MantineProvider. The example's theme/variant are JGuang-authored host props, not universal native component APIs; forceColorScheme synchronizes the app theme. Native implementation source is a reading reference: use npm exports rather than copying internal engines. This batch covers Core, not dates/charts/forms extension packages. Detailed upstream prose remains English.


## Runnable usage

```tsx
import { useState } from 'react';
import * as M from '@mantine/core';
import '@mantine/core/styles.css';


function ComponentPreview({ variant = 'Default' }: { variant?: string }) {
const content = <M.Text>Build something beautiful / 构建美好的界面</M.Text>;
return <M.Box pos="relative" p="xl">{content}<M.Overlay color="#2F67FF" backgroundOpacity={0.15} /></M.Box>;
}
export default function Example({ variant = 'Default', theme = 'light' }: { variant?: string; theme?: 'light' | 'dark' }) {
return <M.MantineProvider forceColorScheme={theme} theme={{ respectReducedMotion: true }}><ComponentPreview variant={variant} /></M.MantineProvider>;
}

```


## Preview states

Default

The example uses the native Mantine API. For supported input demos, change the local variant to Disabled, Invalid or Read only; these are example labels, not new component props. Keep the documented data, controlled values, stores and compound children when adapting the example.



## Usage

`Overlay` takes 100% of the width and height of the parent container or viewport if the `fixed` prop is set.
Set the `color` and `backgroundOpacity` props to change the `Overlay` background-color. Note that the `backgroundOpacity` prop
does not change the CSS opacity property; it changes the background-color. For example, if you set
`color="#000"` and `backgroundOpacity={0.85}`, the background-color will be `rgba(0, 0, 0, 0.85)`:



## Gradient

Set the `gradient` prop to use background-image instead of background-color. When the `gradient` prop is set,
the `color` and `backgroundOpacity` props are ignored.



## Blur

Set the `blur` prop to add `backdrop-filter: blur({value})` styles.
Note that `backdrop-filter` [is not supported in all browsers](https://caniuse.com/css-backdrop-filter).





## Source-backed parameter reference

Implementation signatures and types are generated from the pinned local source. Optional props, native inherited types, union branches and never exclusions are preserved. A forwardRef implementation's ref is a React reference, not an additional business prop.


```ts
Overlay(_props)
```



```ts
export type OverlayStylesNames = 'root';

export type OverlayCssVariables = {
  root: '--overlay-bg' | '--overlay-filter' | '--overlay-radius' | '--overlay-z-index';
};

export interface OverlayProps extends BoxProps, StylesApiProps<OverlayFactory> {
  /** Overlay `background-color` opacity 0–1, ignored when `gradient` prop is set @default 0.6 */
  backgroundOpacity?: number;

  /** Overlay `background-color` @default #000 */
  color?: React.CSSProperties['backgroundColor'];

  /** Overlay background blur in px (converted to rem). Applies `backdrop-filter: blur()`. Note: backdrop-filter is not supported in all browsers. @default 0 */
  blur?: number | string;

  /** Changes overlay to gradient. If set, both `color` and `backgroundOpacity` props are ignored. */
  gradient?: string;

  /** Overlay z-index @default 200 */
  zIndex?: string | number;

  /** Key of `theme.radius` or any valid CSS value to set border-radius @default 0 */
  radius?: MantineRadius;

  /** Content inside overlay */
  children?: React.ReactNode;

  /** Centers content inside the overlay using flexbox (sets display: flex, align-items: center, justify-content: center) @default false */
  center?: boolean;

  /** Changes position from `absolute` to `fixed` (viewport-relative instead of parent-relative) @default false */
  fixed?: boolean;
}

export type OverlayFactory = PolymorphicFactory<{
  props: OverlayProps;
  defaultRef: HTMLDivElement;
  defaultComponent: 'div';
  stylesNames: OverlayStylesNames;
  vars: OverlayCssVariables;
}>;

export type Mod = Record<string, any> | string;

export type BoxMod = Mod | Mod[] | BoxMod[];

export interface BoxProps extends MantineStyleProps {
  /** Class added to the root element, if applicable */
  className?: string | undefined;

  /** Inline style added to root component element, can subscribe to theme defined on MantineProvider */
  style?: MantineStyleProp;

  /** CSS variables defined on root component element */
  __vars?: CssVarsProp;

  /** `size` property passed down the HTML element */
  __size?: string;

  /** Breakpoint above which the component is hidden with `display: none` */
  hiddenFrom?: MantineBreakpoint;

  /** Breakpoint below which the component is hidden with `display: none` */
  visibleFrom?: MantineBreakpoint;

  /** Determines whether component should be hidden in light color scheme with `display: none` */
  lightHidden?: boolean;

  /** Determines whether component should be hidden in dark color scheme with `display: none` */
  darkHidden?: boolean;

  /** Element modifiers transformed into `data-` attributes, for example, `{ 'data-size': 'xl' }`, falsy values are removed */
  mod?: BoxMod;
}

export interface CSSProperties extends React.CSSProperties {
  [key: string]: any;
}

type MantineStyle = CSSProperties | ((theme: MantineTheme) => CSSProperties);

export type MantineStyleProp = MantineStyle | MantineStyle[] | MantineStyleProp[] | undefined;

export type CssVariable = `--${string}`;

export type CssVariables<Variable extends string = CssVariable> = Partial<Record<Variable, string>>;

export type CssVars<Variable extends string = CssVariable> =
  | CssVariables<Variable>
  | ((theme: MantineTheme) => CssVariables<Variable>)
  | CssVars<Variable>[];

export type CssVarsProp<Variable extends string = CssVariable> =
  | CssVars<Variable>
  | CssVars<Variable>[];
```


### Native and external types

External types remain defined by React or native dependencies, not manually expanded into guessed props. The installed version's TypeScript definitions are authoritative.


```ts
PolymorphicFactory<{
  props: OverlayProps;
  defaultRef: HTMLDivElement;
  defaultComponent: 'div';
  stylesNames: OverlayStylesNames;
  vars: OverlayCssVariables;
}>
MantineStyleProps
React.CSSProperties
MantineTheme
Partial<Record<Variable, string>>
Record<Variable, string>
Variable
MantineBreakpoint
Record<string, any>
StylesApiProps<OverlayFactory>
MantineRadius
React.ReactNode
HTMLDivElement
```

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