import type { Surface } from '../types.js';
/** Small cached backdrop map. No hit testing or computed-style reads occur in the particle loop. */
export declare class SnowContrast {
    private doc;
    private columns;
    private rows;
    private cells;
    private support;
    private colors;
    private parser;
    private lastRefresh;
    private dirty;
    private width;
    private height;
    private observer;
    private pending;
    constructor(doc: Document, invalidate: () => void);
    invalidate(): void;
    private color;
    private lightness;
    private strength;
    isPale(css: string): boolean;
    refresh(surfaces: readonly Surface[], width: number, height: number): void;
    at(x: number, y: number): number;
    forSurface(surface: Surface): number;
    destroy(): void;
}
//# sourceMappingURL=Contrast.d.ts.map