/**
 * Returns 'var(--text-primary)' or 'var(--text-primary-on-brand)' depending on which provides
 * better contrast against the given hex background color.
 * Uses the WCAG relative luminance formula.
 */
export declare function getContrastColor(hex: string): 'var(--text-primary)' | 'var(--text-primary-on-brand)';