/**
 * VTD Overlay Feature
 *
 * Displays destination content in a fullscreen iframe overlay when vtd= URL parameter is present.
 * Used for tracking links that redirect to specific content (video, page, etc.).
 *
 * Example: https://example.com/?vt=person_id&vtd=https://youtube.com/watch?v=abc123
 *
 * @see docs/architecture/proposals/vt-vtd-tracking-links.md
 */
import type { VTilt } from "../vtilt";
import type { VTiltConfig } from "../types";
import type { Feature } from "../feature";
export interface VtdOverlayConfig {
    /** Whether the overlay feature is enabled */
    enabled?: boolean;
}
export declare class VtdOverlay implements Feature {
    readonly name = "VtdOverlay";
    private _instance;
    private _config;
    private _isStarted;
    private _destinationUrl;
    private _originalUrl;
    private _isLoading;
    private _container;
    private _iframe;
    private _loadingEl;
    constructor(instance: VTilt, config?: VtdOverlayConfig);
    static extractConfig(config: VTiltConfig): VtdOverlayConfig;
    get isEnabled(): boolean;
    get isStarted(): boolean;
    startIfEnabled(): void;
    stop(): void;
    onConfigUpdate(config: VTiltConfig): void;
    /**
     * Set the destination URL and show the overlay.
     * Called by vtilt.ts when vtd= parameter is detected.
     *
     * @param url - The destination URL (can be URL-encoded)
     */
    setDestinationUrl(url: string): void;
    /**
     * Get the current destination URL.
     */
    getDestinationUrl(): string | null;
    /**
     * Close the overlay with animation.
     */
    close(): void;
    private _isValidUrl;
    /**
     * Transform URLs to embeddable format for known platforms.
     * Many sites block iframe embedding but provide dedicated embed URLs.
     */
    private _toEmbedUrl;
    private _getHostname;
    private _getFaviconUrl;
    private _showOverlay;
    private _destroyOverlay;
    private _attachEventListeners;
    private _getBackdropStyles;
    private _getModalStyles;
    private _getHeaderStyles;
    private _getHeaderHTML;
    private _getIframeWrapperStyles;
    private _getLoadingStyles;
    private _getLoadingHTML;
    private _getIframeStyles;
    private _getGlobalStyles;
    private _truncateUrl;
    private _escapeHtml;
}