/**
 * Gets the version of Tailwind CSS used in the project.
 *
 * This function attempts to read the version from the `tailwindcss/package.json` file.
 *
 * @throws {Error} If the detected Tailwind CSS major version is not 3 or 4
 * @returns {Promise<3 | 4>} `3` if the version is 3.x, `4` if the version is 4.x
 */
export declare function getTailwindVersion(): Promise<3 | 4>;