Slide to confirm

Build an interactive UI element: Slide to confirm.

What it is: Drag the handle to the right; past the mark it finishes on its own.

Behaviour:
- Pill-shaped track of 320 x 64 px with a round white handle with an arrow on the left.
- Drag the handle to the right with pointer events (works with mouse and touch); the label in the track fades as you drag and a coloured fill grows along.
- Release past 80%: the handle slides to the end by itself, the arrow becomes a check and "Confirmed" appears. Release earlier and the handle springs back to the start with a soft ease-out.
- After 2 seconds the element resets.
- Keyboard: Enter or Space on the handle confirms straight away.

Requirements:
- Work in this project's stack. If it is React with Tailwind CSS, make a single component without extra packages; otherwise plain HTML, CSS and JavaScript.
- Fully operable with keyboard and touch, with the right aria attributes.
- Respect prefers-reduced-motion: less or no movement.
- Use the colours, fonts and border radii of my project.
- At the end, show me where the component lives and how to use it.