/**
 * @file Known CSS elements and attributes.
 * TODO: Implement a compatibility table for Extended CSS
 */
/**
 * Legacy Extended CSS attribute prefix.
 *
 * @example
 * ```css
 * [-ext-<name>=...]
 * ```
 */
export declare const LEGACY_EXT_CSS_ATTRIBUTE_PREFIX = "-ext-";
/**
 * ABP Extended CSS prefix.
 *
 * @example
 * ```css
 * [-abp-<name>=...]
 * -abp-<name>(...)
 * ```
 */
export declare const ABP_EXT_CSS_PREFIX = "-abp";
/**
 * Known _strict_ Extended CSS pseudo-classes. Please, keep this list sorted.
 * Strict means that these pseudo-classes are not supported by any browser natively,
 * and they always require Extended CSS libraries to work.
 */
export declare const EXT_CSS_PSEUDO_CLASSES_STRICT: Set<string>;
/**
 * _ALL_ known Extended CSS pseudo-classes. Please, keep this list sorted.
 * It includes strict pseudo-classes and additional pseudo-classes that may be
 * supported by some browsers natively.
 */
export declare const EXT_CSS_PSEUDO_CLASSES: Set<string>;
/**
 * Known legacy Extended CSS attributes. These attributes are deprecated and
 * should be replaced with the corresponding pseudo-classes. In a long term,
 * these attributes will be COMPLETELY removed from the Extended CSS syntax.
 *
 * Please, keep this list sorted.
 */
export declare const EXT_CSS_LEGACY_ATTRIBUTES: Set<string>;
/**
 * Known CSS functions that aren't allowed in CSS injection rules, because they
 * able to load external resources. Please, keep this list sorted.
 */
export declare const FORBIDDEN_CSS_FUNCTIONS: Set<string>;