/**
 * Where a platform draws classic, always-visible scrollbars (Windows, and Linux
 * or macOS when set to always show them), Chromium paints arrow buttons on the
 * thin, colored scrollbars the stylesheet asks for with `scrollbar-width` and
 * `scrollbar-color`. This marks such documents with
 * `data-og-scrollbars="classic"` on <html> so the stylesheet can use a slim
 * rounded thumb there instead. Overlay-scrollbar platforms keep their native
 * scrollbars.
 */
export declare const CLASSIC_SCROLLBARS_ATTRIBUTE = "data-og-scrollbars";
export declare function markClassicScrollbars(doc?: Document | undefined): void;