The var() Function

Question

Variables in CSS should be declared within a CSS selector that defines its scope. For a global scope you can use either the :root or the body selector.

The variable name must begin with two dashes (--) and is case sensitive!

The syntax of the var() function is as follows:

var(custom-name, value)

Answer 1

you have to use quotes in this text and add the souece reference
https://www.w3schools.com/css/css3_variables.asp

Answer 2

I am member freecodecamp group somebody public an video of the use of 3d button in the code used var in css. Change the values to numbers make more usability with javascript.