import { type Font } from '@capsizecss/unpack';
export type FontFaceMetrics = Pick<Font, 'ascent' | 'descent' | 'lineGap' | 'unitsPerEm' | 'xWidthAvg'>;
export declare function readMetrics(family: string, buffer: Buffer): Promise<FontFaceMetrics>;
export declare function generateFallbackFontFace({ metrics, fallbackMetrics, name: fallbackName, font: fallbackFontName, properties, }: {
    metrics: FontFaceMetrics;
    fallbackMetrics: FontFaceMetrics;
    name: string;
    font: string;
    properties: Record<string, string | undefined>;
}): string;
