export type Rgb = readonly [number, number, number];
export interface Ink {
    /** Dark substrate: the ink is mirrored so near marks read bright. */
    dark: boolean;
    /** Gradient stops, left → right. Empty = upstream's grey ink. */
    ramp: readonly Rgb[];
    /** CSS-px frame width the ramp is laid across. */
    size: number;
}
export declare function monoInk(dark: boolean): Ink;
/**
 * Fill or stroke style for one mark. `white` is upstream's ink value
 * (0 = darkest ink on paper); `x` is the mark's projected CSS-px position.
 */
export declare function inkStyle(ink: Ink, white: number, x: number, alpha: number): string;
/**
 * Resolve a CSS colour to sRGB by painting one pixel — the canvas accepts
 * hex, rgb(), hsl(), names and the CSS Color 4 spaces alike. Returns null
 * for anything the canvas rejects (including `var(...)`).
 */
export declare function parseColor(css: string): Rgb | null;
/** Gradient ink from CSS stops; falls back to grey when none of them parse. */
export declare function gradientInk(dark: boolean, size: number, stops: readonly string[]): Ink;