import { type AttributeReactiveClass } from '../../element-reactive/index.js';
export declare class Placeholder implements InstanceType<AttributeReactiveClass<typeof HTMLElement>> {
    #private;
    static observedAttributes: string[];
    _handlerPlaceholder: (this: void, newVal: string | null) => void;
    _handlerPlaceholderColor: (this: void, newVal: string | null) => void;
    _handlerPlaceholderFontFamily: (this: void, newVal: string | null) => void;
    _handlerPlaceholderFontSize: (this: void, newVal: string | null) => void;
    _handlerPlaceholderFontWeight: (this: void, newVal: string | null) => void;
    constructor(dom: HTMLElement);
}