export declare const isSafeCssVarSegment: (segment: string) => boolean;
export declare const serializeOverrideCssValue: (value: unknown) => string | null;
export declare const flattenToVars: (obj: Record<string, any>, onError: (msg: string) => void, prefix?: string) => string;
export declare const loadFont: (url: string) => void;
export declare const loadDevTheme: () => Promise<{
    light: any;
    dark: any;
}>;
export declare function deepMergeNonEmpty(base: Record<string, any>, override: Record<string, any>): Record<string, any>;