/**
 * Sets the theme on the document root element.
 * Pass "light", "dark", or "system" (removes data-theme to fall back to OS preference).
 */
export declare function setTheme(theme: "light" | "dark" | "system"): void;
/**
 * Returns the current active theme: "light", "dark", or "system" (when no override is set).
 */
export declare function getTheme(): "light" | "dark" | "system";
/**
 * Toggles between light and dark. If currently "system", reads the OS preference
 * and toggles to the opposite.
 */
export declare function toggleTheme(): void;