type State = {
    browserFontSize: number;
    documentFontSize: number;
    fixedFontSize: number;
};
type OnChangeHandler = (state: State) => void;
declare class BrowserFontSizeObserver {
    #private;
    constructor(onChangeHandler?: OnChangeHandler);
    disconnect(): void;
    get state(): State;
}
export default BrowserFontSizeObserver;