# Core/Drawer - Usage

### Implementation

The drawer UI is rendered in a **portal** (default `document.body`), with `position: fixed` and `top`/`bottom` anchoring so the sheet fills the **layout viewport** (the browser window on a real site; the Storybook **preview iframe** in docs/canvas). In the **Story** canvas, a decorator stretches the preview document so the iframe can grow with the panel; that shell is **skipped in Docs** so embedded previews are not forced to full-viewport height. The open drawer still fills the iframe, not the inline story box—resize the preview panel if you need a taller canvas.

### Header

The header is the `title` slot: a string for a single heading, or a composition with `Drawer.Heading`, optional `Drawer.Description`, `Drawer.ExpandedTitleLayout`, and the shared `Breadcrumbs` components (matching the `Modal` pattern). The header stays pinned while the body scrolls.