# XWUICountdownTimer

General-purpose countdown to an absolute ISO `targetDate` or a relative
`durationSeconds`. Ticks once per second, pauses while the tab is hidden, and
emits a `complete` event at zero.

## Choosing a format

- `compact` - `2d 04h 12m`. Use in dense rows and table cells.
- `segmented` - boxed DD / HH / MM / SS. Use for launch and sale headers.
- `digital` - `04:12:33`. Use when the countdown reads like a clock.

## Basic Usage

```html
<xwui-countdown-timer
    target-date="2026-12-31T23:59:59Z"
    format="segmented"
    show-labels="true"
    complete-text="Launched">
</xwui-countdown-timer>
```

## Absolute vs relative

`targetDate` survives a reload, a timezone change and a backgrounded tab,
because it is an instant rather than a remaining amount. `durationSeconds`
restarts from the top every time the component mounts - correct for a quiz
timer, wrong for a sale that ends at a fixed moment. Prefer `targetDate` unless
you actually mean "from now".

The tick pauses while the document is hidden, so the displayed value is
recomputed from the clock on resume rather than accumulated from ticks; a tab
left in the background for an hour still shows the right number.

## API

```api
```