Answer 1

Hi,
The CSS parameters (named var()) are custom css properties that you can declare in a particular section of style named :root and you can reuse in your css as value by adding the syntax:
cssproperty: var(--yourprop);
The scope is: if you declare a single variable in the :root, you can reuse it in all css.
An example on this code:
https://code.sololearn.com/Wr8i1oKcVdIo/?ref=app