# Browser support

Fluidbox targets current browsers. Its gestures, flights and body-level viewer each have one implementation, with no legacy fallbacks.

## Supported browsers

| Browser | Versions |
| --- | --- |
| Chrome and Edge, desktop | The current and previous stable major versions. |
| Firefox, desktop | The current and previous stable major versions. |
| Safari, macOS and iOS | The Safari of the current and previous OS major releases. |
| Chrome, Android | The current and previous stable major versions. |

The table doesn't cover embedded web views, in-app browsers or Firefox ESR.

## What the browser needs

The viewer uses these platform features. Every supported browser has them.

- CSS: scroll snapping, `:has()`, `:where()`, `@property`, container query units (`cqw`), small viewport units (`svh`), `env(safe-area-inset-*)`.
- DOM: Pointer Events, Web Animations, the `inert` attribute, `ResizeObserver`, `IntersectionObserver`, `HTMLImageElement.decode()`.
- The sheet also uses `AbortSignal.any()`.

The package root and the add-on entries touch no browser globals on import, so they also load in Node, Bun, Deno and edge runtimes for server rendering. See [Getting started](https://fluidbox.dwe.workers.dev/docs/getting-started.md#server-rendering).

## Progressive features

The viewer uses these where the browser has them, and works without them:

| Feature | Without it |
| --- | --- |
| Scroll-driven animations (`animation-timeline: scroll()`) | The sheet still scrolls and snaps between its stops, but the photo keeps its size behind it and the backdrop doesn't fade with a scroll dismiss. |
| The `scrollend` event | The viewer waits for a short pause in scroll events instead. |
| `visualViewport` | The sheet doesn't make room for the software keyboard. |

## Motion preferences

With `prefers-reduced-motion: reduce`, the viewer opens and closes without flights and moves between slides, zoom levels and sheet stops without animation. See [Styling](https://fluidbox.dwe.workers.dev/docs/styling.md#reduced-motion).