/**
 * 弹出层管理工具
 * 统一管理弹出层的 z-index、滚动锁定、Escape 关闭
 */
/** 获取下一个 z-index */
export declare function getNextZIndex(): number;
/** 锁定 body 滚动 */
export declare function lockScroll(): void;
/** 解锁 body 滚动 */
export declare function unlockScroll(): void;
/** 计算弹出层位置 */
export interface PopupPosition {
    top: number;
    left: number;
}
export type Placement = 'top' | 'top-start' | 'top-end' | 'bottom' | 'bottom-start' | 'bottom-end' | 'left' | 'left-start' | 'left-end' | 'right' | 'right-start' | 'right-end';
export declare function computePosition(triggerRect: DOMRect, popupWidth: number, popupHeight: number, placement?: Placement, gap?: number): PopupPosition;
