/**
 * Sanitizes HTML content to prevent XSS attacks.
 */
export declare class ContentSanitizer {
    /** Custom safe tags */
    private readonly customSafeTags;
    /** Custom safe attributes */
    private readonly customSafeAttributes;
    /**
     * Creates a new ContentSanitizer.
     * @param options - Sanitizer options
     */
    constructor(options?: {
        additionalTags?: string[];
        additionalAttributes?: string[];
    });
    /**
     * Sanitizes HTML content.
     * @param html - HTML to sanitize
     * @returns Sanitized HTML
     */
    sanitize(html: string): string;
    /**
     * Sanitizes plain text (escape HTML).
     * @param text - Text to sanitize
     * @returns Escaped text
     */
    sanitizeText(text: string): string;
    /**
     * Validates content against dangerous patterns.
     * @param content - Content to validate
     * @returns Whether content is safe
     */
    validate(content: string): boolean;
    /**
     * Sanitizes HTML using DOM parsing.
     * @param html - HTML to sanitize
     * @returns Sanitized HTML
     */
    private sanitizeWithDOM;
    /**
     * Recursively sanitizes a DOM node.
     * @param node - Node to sanitize
     */
    private sanitizeNode;
    /**
     * Sanitizes CSS style content using allowlist approach.
     */
    private sanitizeStyle;
    /**
     * Checks if a CSS value contains dangerous patterns.
     */
    private containsDangerousCSSValue;
}