import type { Spread } from '../engine/spread';
import { type FlipDirection, type LayoutMetrics, type Renderer, type RenderOptions, type SpreadContent } from './types';
/**
 * Baseline renderer: a 2-panel CSS-3D fold. Runs on every browser, no GPU. Pages
 * are <canvas> elements; the turning leaf (front + back faces, backface-hidden)
 * rotates about the spine driven by flipProgressToPose(), with a gradient shadow
 * overlay for depth. `beginFlip` stages the surfaces; `setFlipProgress` animates.
 */
export declare class CssRenderer implements Renderer {
    #private;
    mount(container: HTMLElement): Promise<void>;
    destroy(): void;
    renderSpread(_spread: Spread, content: SpreadContent, options?: RenderOptions): void;
    beginFlip(from: SpreadContent, to: SpreadContent, direction: FlipDirection, options?: RenderOptions): void;
    setFlipProgress(t: number, direction: FlipDirection): void;
    setViewTransform(scale: number, x: number, y: number): void;
    measure(): LayoutMetrics;
}