import type { LexicalEditor, DOMExportOutputMap, DOMConversionMap } from 'lexical';
/**
 * Merge a CSS property into an existing CSS text string.
 * Replaces the property if it already exists, appends it otherwise.
 * If value is empty, removes the property.
 */
export declare function mergeElementStyle(cssText: string, prop: string, value: string): string;
/**
 * Extract a single CSS property value from a CSS text string.
 */
export declare function getElementStyleProperty(cssText: string, prop: string): string;
/**
 * Plugin that synchronizes ElementNode.__style to the DOM.
 *
 * Lexical's reconciler does not apply ElementNode.__style to the DOM
 * automatically. This plugin bridges that gap by listening for updates
 * and syncing background-color from node state to the DOM element.
 */
export declare function registerElementStylePlugin(editor: LexicalEditor): () => void;
/**
 * Build an html.export Map that overrides exportDOM for block element nodes
 * to include __style (background-color) in the serialized HTML.
 */
export declare function buildElementStyleExportMap(): DOMExportOutputMap;
/**
 * Build an html.import DOMConversionMap that preserves background-color
 * from imported HTML elements onto the Lexical node style.
 */
export declare function buildElementStyleImportMap(): DOMConversionMap;
/**
 * Default set of CSS properties to preserve on inline text nodes during
 * HTML import. Matches the properties the toolbar applies via
 * `$patchStyleText()`.
 */
export declare const DEFAULT_INLINE_STYLE_PROPERTIES: readonly string[];
/**
 * Build a DOMConversionMap that preserves inline CSS styles from inline
 * HTML elements onto Lexical TextNode.__style.
 *
 * Also replicates Lexical's default format toggling (bold from
 * font-weight, italic from font-style, etc.) since our priority-1
 * handler replaces the default priority-0 handler.
 *
 * @param properties - CSS properties to preserve. Defaults to
 *   {@link DEFAULT_INLINE_STYLE_PROPERTIES}.
 */
export declare function buildInlineStyleImportMap(properties?: readonly string[]): DOMConversionMap;
/**
 * Build a combined DOMConversionMap that preserves styles for both
 * block-level elements (text-align, background-color on p/h1-h6)
 * and inline elements (color, font-size, font-family, background-color
 * on span/em/strong/etc.).
 *
 * @param inlineProperties - CSS properties to preserve on inline text
 *   nodes. Defaults to {@link DEFAULT_INLINE_STYLE_PROPERTIES}.
 */
export declare function buildStyleImportMap(inlineProperties?: readonly string[]): DOMConversionMap;