Reply To: Modifications – Product Page

2) Where can I put this css?

Please, help me with these things (Previous question):
1) Tooltip hover image in the swatches with name of variation
3) Calculate shipping cost in the product page

In what files should I modify? Only say this for me.

My website will be used on woodmart themeforest description, Artem talked with me and I approved.

I just need some orientation to do these modifications.