/**
 * @file Progressive Enhancement Utilities
 * @description Utility functions and constants for progressive enhancement
 */
/**
 * Default browser capabilities for SSR
 */
export declare const DEFAULT_CAPABILITIES: {
    readonly esModules: true;
    readonly asyncAwait: true;
    readonly webGL: true;
    readonly webGL2: true;
    readonly webP: true;
    readonly avif: true;
    readonly serviceWorker: true;
    readonly webWorker: true;
    readonly sharedArrayBuffer: false;
    readonly intersectionObserver: true;
    readonly resizeObserver: true;
    readonly cssGrid: true;
    readonly containerQueries: true;
    readonly cssHas: true;
    readonly viewTransitions: true;
    readonly navigationAPI: true;
    readonly broadcastChannel: true;
    readonly webLocks: true;
    readonly storage: true;
    readonly indexedDB: true;
    readonly webAssembly: true;
    readonly bigInt: true;
    readonly proxy: true;
    readonly weakMap: true;
    readonly fetch: true;
    readonly streams: true;
    readonly modules: true;
    readonly dynamicImport: true;
    readonly topLevelAwait: true;
    readonly popoverAPI: true;
    readonly webAnimations: true;
    readonly idleCallback: true;
    readonly intl: true;
};
/**
 * Get default capabilities
 */
export declare function getDefaultCapabilities(): typeof DEFAULT_CAPABILITIES;
/**
 * Check WebP support asynchronously
 */
export declare function checkWebPSupport(): Promise<boolean>;
/**
 * Check AVIF support asynchronously
 */
export declare function checkAVIFSupport(): Promise<boolean>;
/**
 * Check async/await support
 */
export declare function hasAsyncAwait(): boolean;
/**
 * Check WebGL support
 */
export declare function hasWebGL(): boolean;
/**
 * Check WebGL2 support
 */
export declare function hasWebGL2(): boolean;
/**
 * Create a progressive feature definition
 */
export declare function createFeature(id: string, config: {
    loader: () => Promise<unknown>;
    dependencies?: string[];
    polyfill?: () => Promise<void>;
    requirements?: Array<keyof typeof DEFAULT_CAPABILITIES>;
    fallback?: () => Promise<unknown>;
    priority?: 'critical' | 'high' | 'normal' | 'low';
    preload?: boolean;
}): {
    id: string;
    loader: () => Promise<unknown>;
    dependencies?: string[];
    polyfill?: () => Promise<void>;
    requirements?: Array<keyof typeof DEFAULT_CAPABILITIES>;
    fallback?: () => Promise<unknown>;
    priority?: 'critical' | 'high' | 'normal' | 'low';
    preload?: boolean;
};
/**
 * Browser capabilities interface
 */
export interface BrowserCapabilities {
    /** Supports ES modules */
    esModules: boolean;
    /** Supports async/await */
    asyncAwait: boolean;
    /** Supports WebGL */
    webGL: boolean;
    /** Supports WebGL2 */
    webGL2: boolean;
    /** Supports WebP images */
    webP: boolean;
    /** Supports AVIF images */
    avif: boolean;
    /** Supports Service Workers */
    serviceWorker: boolean;
    /** Supports Web Workers */
    webWorker: boolean;
    /** Supports SharedArrayBuffer */
    sharedArrayBuffer: boolean;
    /** Supports IntersectionObserver */
    intersectionObserver: boolean;
    /** Supports ResizeObserver */
    resizeObserver: boolean;
    /** Supports CSS Grid */
    cssGrid: boolean;
    /** Supports CSS Container Queries */
    containerQueries: boolean;
    /** Supports CSS :has() */
    cssHas: boolean;
    /** Supports View Transitions API */
    viewTransitions: boolean;
    /** Supports Navigation API */
    navigationAPI: boolean;
    /** Supports Popover API */
    popoverAPI: boolean;
    /** Supports Web Animations API */
    webAnimations: boolean;
    /** Supports requestIdleCallback */
    idleCallback: boolean;
    /** Supports Intl API */
    intl: boolean;
}
/**
 * Detect browser capabilities
 */
export declare function detectCapabilities(): BrowserCapabilities;
/**
 * Get capabilities without React
 */
export declare function getCapabilities(): BrowserCapabilities;