import { default as React } from 'react';
/**
 * Critical CSS configuration
 */
export interface CriticalCSSConfig {
    /** Viewport height for critical path (default: 100vh) */
    viewportHeight?: number;
    /** Enable automatic extraction */
    autoExtract?: boolean;
    /** Cache extracted CSS */
    cacheCSS?: boolean;
    /** Route patterns for route-specific CSS */
    routePatterns?: Record<string, string[]>;
    /** Enable debug logging */
    debug?: boolean;
}
/**
 * CSS rule classification
 */
export type CSSRuleType = 'critical' | 'above-fold' | 'deferred' | 'unused';
/**
 * Analyzed CSS rule
 */
export interface AnalyzedCSSRule {
    /** CSS selector */
    selector: string;
    /** CSS declarations */
    declarations: string;
    /** Full rule text */
    ruleText: string;
    /** Classification */
    type: CSSRuleType;
    /** Specificity score */
    specificity: number;
    /** Source stylesheet */
    source?: string;
}
/**
 * Critical CSS result
 */
export interface CriticalCSSResult {
    /** Critical CSS for immediate inline */
    critical: string;
    /** Above-fold CSS (important but can be slightly deferred) */
    aboveFold: string;
    /** Deferred CSS (load async) */
    deferred: string;
    /** Unused CSS (can be removed) */
    unused: string;
    /** LCP element styles */
    lcpStyles: string;
    /** Font preload hints */
    fontPreloads: string[];
    /** Extraction timestamp */
    timestamp: number;
}
/**
 * Font resource
 */
export interface FontResource {
    /** Font family */
    family: string;
    /** Font URL */
    url: string;
    /** Font weight */
    weight?: string;
    /** Font style */
    style?: string;
    /** Unicode range */
    unicodeRange?: string;
    /** Format */
    format?: string;
}
/**
 * CSS containment options
 */
export interface ContainmentOptions {
    /** Layout containment */
    layout?: boolean;
    /** Paint containment */
    paint?: boolean;
    /** Size containment */
    size?: boolean;
    /** Style containment */
    style?: boolean;
    /** Content visibility */
    contentVisibility?: 'auto' | 'hidden' | 'visible';
}
/**
 * Extracts and categorizes critical CSS
 */
export declare class CriticalCSSExtractor {
    private static instance;
    private config;
    private analyzer;
    private cache;
    constructor(config?: CriticalCSSConfig);
    /**
     * Get singleton instance
     */
    static getInstance(config?: CriticalCSSConfig): CriticalCSSExtractor;
    /**
     * Reset singleton (for testing)
     */
    static reset(): void;
    /**
     * Extract critical CSS
     */
    extract(routePath?: string): CriticalCSSResult;
    /**
     * Clear cache
     */
    clearCache(): void;
    /**
     * Extract LCP element styles
     */
    private extractLCPStyles;
    /**
     * Generate unique selector for element
     */
    private generateSelector;
    /**
     * Extract font preload URLs
     */
    private extractFontPreloads;
    /**
     * Minify CSS (simple minification)
     */
    private minifyCSS;
    /**
     * Debug logging
     */
    private log;
}
/**
 * Inject critical CSS inline
 */
export declare function injectCriticalCSS(css: string, id?: string): HTMLStyleElement;
/**
 * Load CSS asynchronously
 */
export declare function loadCSSAsync(href: string, id?: string): Promise<void>;
/**
 * Preload font
 */
export declare function preloadFont(url: string, crossOrigin?: boolean): HTMLLinkElement;
/**
 * Apply CSS containment to element
 */
export declare function applyContainment(element: HTMLElement, options: ContainmentOptions): void;
/**
 * Hook for critical CSS extraction and injection
 */
export declare function useCriticalCSS(config?: CriticalCSSConfig): {
    result: CriticalCSSResult | null;
    extract: () => CriticalCSSResult;
    inject: () => void;
    isExtracted: boolean;
};
/**
 * Hook for CSS containment
 */
export declare function useCSSContainment(options?: ContainmentOptions): React.RefObject<HTMLDivElement | null>;
/**
 * Hook for deferred CSS loading
 */
export declare function useDeferredCSS(stylesheets: string[], options?: {
    loadOnIdle?: boolean;
}): {
    loaded: boolean;
    load: () => Promise<void>;
};
/**
 * Get the global critical CSS extractor
 */
export declare function getCriticalCSSExtractor(config?: CriticalCSSConfig): CriticalCSSExtractor;
/**
 * Reset the extractor (for testing)
 */
export declare function resetCriticalCSSExtractor(): void;
/**
 * Extract and inject critical CSS in one call
 */
export declare function extractAndInjectCriticalCSS(config?: CriticalCSSConfig): CriticalCSSResult;
declare const _default: {
    CriticalCSSExtractor: typeof CriticalCSSExtractor;
    getCriticalCSSExtractor: typeof getCriticalCSSExtractor;
    resetCriticalCSSExtractor: typeof resetCriticalCSSExtractor;
    extractAndInjectCriticalCSS: typeof extractAndInjectCriticalCSS;
    injectCriticalCSS: typeof injectCriticalCSS;
    loadCSSAsync: typeof loadCSSAsync;
    preloadFont: typeof preloadFont;
    applyContainment: typeof applyContainment;
    useCriticalCSS: typeof useCriticalCSS;
    useCSSContainment: typeof useCSSContainment;
    useDeferredCSS: typeof useDeferredCSS;
};
export default _default;