/**
 * SSR-friendly CSS helpers.
 *
 * These utilities are CSS/media-query based (no window access), so they are
 * safe to use in Server Components and during SSR.
 */
export declare const SSR_BREAKPOINTS: {
    readonly xs: 0;
    readonly sm: 640;
    readonly md: 768;
    readonly lg: 1024;
    readonly xl: 1280;
};
export type SsrBreakpoint = keyof typeof SSR_BREAKPOINTS;
type ResponsiveMap<T> = Partial<Record<SsrBreakpoint, T>> & {
    base?: T;
};
/**
 * Builds a min-width media query string for a breakpoint.
 */
export declare function ssrUp(bp: Exclude<SsrBreakpoint, 'xs'>): string;
/**
 * Builds a max-width media query string for a breakpoint.
 */
export declare function ssrDown(bp: Exclude<SsrBreakpoint, 'xs'>): string;
/**
 * Builds a min/max media query string between two breakpoints.
 */
export declare function ssrBetween(min: Exclude<SsrBreakpoint, 'xs'>, max: Exclude<SsrBreakpoint, 'xs'>): string;
/**
 * Converts responsive values to a StyleX-friendly CSS object shape.
 *
 * Example:
 *   ssrCss({
 *     fontSize: ssrResponsive({ base: '14px', md: '16px', lg: '18px' })
 *   })
 */
export declare function ssrResponsive<T>(values: ResponsiveMap<T>): Record<string, T>;
/**
 * Identity helper for readability when defining SSR-safe style objects.
 */
export declare function ssrCss<T extends Record<string, unknown>>(styles: T): T;
export {};