/**
 * Given one base hex color, returns 3 gradient shades and CSS values.
 * - If base is light (high luminance): gradient goes base → darker shades.
 * - If base is dark: gradient goes lighter shades → base.
 */
export declare function hexLuminance(hex: string): number;
export declare function darkenHex(hex: string, amount: number): string;
export type GradientShades = {
    /** Base color (--full-main-bg). */
    main: string;
    /** Outer / extreme shade (--full-outer-bg). */
    outer: string;
    /** First gradient stop. */
    shade1: string;
    /** Second gradient stop. */
    shade2: string;
    /** Full CSS linear-gradient for --full-bg-effect. */
    gradient: string;
};
/**
 * Returns 3 shades from one base color.
 * - Light base → main, darker, darkest (gradient goes to darker).
 * - Dark base → lightest, lighter, main (gradient goes to lighter).
 */
export declare function getGradientShades(baseHex: string): GradientShades;