Достать оттуда https://underscores.me/
Из файла https://wylsa.com/wp-content/themes/wylsa/style.css
Theme Name: Wylsacom Media
Theme URI: http://underscores.me/
Author: Alexander Kuprianov
Author URI: alikkuprianov.ru
Description: Wylsacom Media
License: GNU General Public License v2 or later
License URI: LICENSE
Text Domain: Wylsa
This theme, like WordPress, is licensed under the GPL.
Use it to make something cool, have fun, and share what you've learned with others.
wylsa is based on Underscores https://underscores.me/, (C) 2012-2017 Automattic, Inc.
Underscores is distributed under the terms of the GNU GPL v2 or later.
Normalizing styles have been helped along thanks to the fine work of
Nicolas Gallagher and Jonathan Neal https://necolas.github.io/normalize.css/