/**
 * Chapter navigation helpers for the desktop UI plugin.
 *
 * Owns: `findChapterTitle`, `previousChapter`, `nextChapter`.
 *
 * Chapter marker DOM construction lives in `progressBar.ts`
 * (`buildChapterMarkers`, `updateChapterProgress`, `updateChapterBuffer`,
 * `updateChapterHover`). This module adds the navigation and lookup
 * layer on top.
 *
 * Integration: called from `DesktopUiPlugin` — the class threads in the
 * player instance rather than exposing internals.
 */
import type { IVideoPlayer, VideoPlaylistItem } from '../../../index.js';
/**
 * Find the title of the chapter whose range covers `time`.
 * Returns `undefined` when no chapter covers the position.
 */
export declare function findChapterTitle(player: IVideoPlayer<VideoPlaylistItem>, time: number): string | undefined;
/**
 * Seek to the start of the previous chapter relative to `time`.
 * If the current time is within the first second of a chapter, seeks to the
 * chapter before it. Falls back to time 0 when no earlier chapter exists.
 */
export declare function previousChapter(player: IVideoPlayer<VideoPlaylistItem>): void;
/**
 * Seek to the start of the next chapter relative to `time`.
 * No-ops when already past the last chapter boundary.
 */
export declare function nextChapter(player: IVideoPlayer<VideoPlaylistItem>): void;