The book’s website at https://thevalebook.com/ has a ‘Resources’ section (top right of the site’s home page) which contains a link with text ‘Download the completed AwesomeCo style files’ that points to https://thevalebook.com/awesomeco.zip. Following this link causes a 404. In Safari I get this message:
Not Found
The requested URL was not found on this server.
Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.’