Isearched how to set a font to a Xojo Desktop application that creates (export) a ListBox contents into an html file and found @ w3schools the solution.
It also appears that I loved the google fonts idea and the Sofia Font.
So, I implemented that as a custom stylesheet.
Last nigh, I had a question: “What will happens if Internet is off ?”.
I was disconnected some minutes ago and the answer is (of course may I say ?): the default font (I do not set one, but I will now) is used since Sofia is not available.
So, as the tile say: warning. But, now you know and can make decisions.
BTW: once more, this is about a Desktop application. BUT, you can use that n web application(s) and t may be a different matter: if no internet, no running web application