/** Panel entrance class; its CSS declaration also carries the transition. */
export declare const SETTINGS_PANEL_CLASS = "dsu-settings-panel";
/** Page cross-fade marker; the replay itself is the imperative animation. */
export declare const SETTINGS_PAGE_CLASS = "dsu-settings-page";
/** Mask entrance marker; the fade itself is the imperative animation. */
export declare const SETTINGS_MASK_CLASS = "dsu-settings-mask";
/** Applied to the live panel while it shrinks out, before the close lands. */
export declare const SETTINGS_CLOSING_CLASS = "dsu-settings-closing";
/** Applied to the live mask while the panel shrinks out. */
export declare const SETTINGS_MASK_CLOSING_CLASS = "dsu-settings-mask-closing";
/** Upper bound for the exit transition (opacity 160ms + scale 280ms, plus margin). */
export declare const EXIT_TIMEOUT_MS = 380;
/** Engine wiring: the settings-motion toggle. */
export interface SettingsMotionOptions {
    /** Read the current settings-motion toggle (default on until resolved). */
    enabled: () => boolean;
    /** Subscribe to toggle changes; returns the disposer. */
    subscribe: (listener: () => void) => () => void;
    /**
     * Whether the width-slider preview is open (the panel hidden behind the
     * floating slider). Escape belongs to the preview then - neither swallowing it
     * nor letting it through, or one keypress would leave the preview *and* close
     * the panel. Injected by the wiring (client/index.ts) so motion/ never reads
     * core/ state on its own.
     *
     * Not to be confused with `innerLayerOpen()`: that one is a Menu or a nested
     * modal *inside* the panel.
     */
    isPreviewOpen: () => boolean;
}
/** Installed settings-motion handle. */
export interface SettingsMotionHandle {
    /** Stop observing and drop every applied class. */
    dispose: () => void;
}
/**
 * Install the settings-panel motion observer.
 * @param options - the settings-motion toggle access.
 * @returns the handle that removes the observer and the applied classes.
 */
export declare function installSettingsMotion(options: SettingsMotionOptions): SettingsMotionHandle;