yarn watchcommand is running let's go to
xampp/htdocs/zero-one/assets/app/custom/folder. That folder contains all Zero One theme files.
xampp/htdocs/zero-one/assets/app/custom/folder override and extend core Uikit files in
xampp/htdocs/zero-one/assets/app/src/less/folder and are compiled as CSS files in to
xampp/htdocs/zero-one/assets/app/custom/elements/variables.lessand open it with your favorite code editor, or text editor.
variables.cssfile new CSS theme file will be generated. It takes 5 - 10 seconds. And you can check changes by refreshing the localhost website in the browser.