In the Seaside book, chapter 17.2 I read I can include a stylesheet this way :

updateRoot: anHtmlRoot
    super updateRoot: anHtmlRoot.
    anHtmlRoot stylesheet url: 'http://seaside.st/styles/main.css'

On my development machine (macOS) I use http://localhost:8080/myApp as the server address and I don�t know the root directory of the Seaside integrated web server.

Can anyone help me to find this directory?

Thanks.