I am trying to create an offline website using the CSS template fro w3schools.com. I wanted to check if the template has any external reference or not. As if it has i the site might malfunction. I have checked myself but it would be very helpful if anybody else could check and confirm.
Template Link- http://www.w3schools.com/lib/w3.css
Nope, there is no reference. In any case you should have tried it by yourself: import the CSS file in an HTML and check if your browser downloads anything else.
For example, in chrome you can go to
Devtools > Sources > Sources and check all the resources/dependencies the website relies on. For example, this is what I see here in stackoverflow: