/** Timing for one block's reveal. */
export interface TextRevealOptions {
    /** How fast one line is wiped in (ms per line). */
    perLineMs?: number;
    /** Lower bound on the wipe (ms). */
    minMs?: number;
    /** Upper bound on the wipe (ms): a long block must not crawl. */
    maxMs?: number;
    /** Delay before the wipe starts (ms). */
    delayMs?: number;
}
/**
 * Reveal one text block line by line under a clip mask. Belongs to text that
 * appears ONCE - a thought body being expanded, a welcome headline - because text
 * the user is already reading must never be re-revealed.
 *
 * The wipe is timed from the block's own box: the line count is estimated from
 * its rendered height and its line-height, so a long thought prints slowly and a
 * two-line block does not crawl. Where there is no layout (jsdom) it degrades to
 * the lower bound, and without WAAPI it is a no-op that still reports the timing.
 * @param el - the block to reveal.
 * @param options - timing overrides.
 * @returns the wipe duration in ms.
 */
export declare function revealTextBlock(el: HTMLElement, options?: TextRevealOptions): number;