/**
 * @zendir/ui - Responsive Breakpoint System
 *
 * Breakpoints aligned with Astro UX Design System responsive guidelines.
 * Supports mission control displays (4K) down to mobile field devices.
 *
 * Breakpoints:
 * - sm:  640px  — Mobile landscape / small tablets
 * - md:  768px  — Tablets
 * - lg:  1024px — Laptops / desktop
 * - xl:  1280px — Large monitors
 * - xxl: 1920px — Mission control displays (HD)
 *
 * @example
 * ```tsx
 * const { isMobile, isTablet, isDesktop, breakpoint, width } = useBreakpoint();
 * ```
 */
export type Breakpoint = "base" | "sm" | "md" | "lg" | "xl" | "xxl";
/** Responsive value: single value or [base, sm?, md?, lg?, xl?, xxl?] */
export type ResponsiveValue<T> = T | [T, T?, T?, T?, T?, T?];
export declare const BREAKPOINTS: {
    readonly base: 0;
    readonly sm: 640;
    readonly md: 768;
    readonly lg: 1024;
    readonly xl: 1280;
    readonly xxl: 1920;
};
export interface UseBreakpointReturn {
    /** Current breakpoint name */
    breakpoint: Breakpoint;
    /** Current viewport width in px */
    width: number;
    /** True when viewport < 768px (base, sm) */
    isMobile: boolean;
    /** True when viewport >= 768px and < 1024px */
    isTablet: boolean;
    /** True when viewport >= 1024px */
    isDesktop: boolean;
    /** True when viewport >= 1920px (mission control) */
    isWidescreen: boolean;
    /** Check if viewport is at or above a given breakpoint */
    isAbove: (bp: Breakpoint) => boolean;
    /** Check if viewport is below a given breakpoint */
    isBelow: (bp: Breakpoint) => boolean;
}
/**
 * Hook for responsive breakpoint detection.
 *
 * Uses matchMedia for efficient, debounce-free breakpoint tracking.
 * Respects SSR by defaulting to 'lg' (desktop).
 *
 * @example
 * ```tsx
 * const { isMobile, isDesktop, breakpoint } = useBreakpoint();
 *
 * return (
 *   <Grid columns={isMobile ? 1 : 3}>
 *     ...
 *   </Grid>
 * );
 * ```
 */
export declare function useBreakpoint(): UseBreakpointReturn;
/**
 * Resolve a responsive value based on current breakpoint.
 *
 * Given `[1, 2, 3]` at breakpoint 'lg', returns 3.
 * Falls back to the last defined value for higher breakpoints.
 *
 * @example
 * resolveResponsiveValue([1, 2, 3], 'lg') // → 3
 * resolveResponsiveValue([1, 2], 'xl')     // → 2 (falls back to last defined)
 * resolveResponsiveValue(5, 'md')          // → 5 (non-array passthrough)
 */
export declare function resolveResponsiveValue<T>(value: ResponsiveValue<T>, breakpoint: Breakpoint): T;