Thank you so much. It's working

I have added this code to base.css, main-product.css and also try with other css file. But not working

Sorry! but i don't found any theme.css

Which main css file please tell me?

https://q5pxkymzh6c3lgio-57568395417.shopifypreview.comThis is the url of copy website. 

It is copy theme preview url

https://www.lumimour.com/?_ab=0&_fd=0&_sc=1.This is url for copy theme

Yes. I am working of copy of my theme

https://www.lumimour.com/

I have added Add to cart button below products on collection page and main home page. Desktop view is perfect but in mobile view it didn't allign in a line. Please help me

This code is not working