Magento 2: how to add css ONLY to custom module

I created a custom module that overrides the addtocart.phtml file. In that module, I also created a css file.
Here is what I did:

Here is my layout – catalog_product_view.xml:

< ?xml version="1.0"?>

    
        
     
    
        
            
                Vendor_Module::product/view/addtocart.phtml
            
        
        
            
                Vendor_Module::product/view/addtocart.phtml
            
        
    

and then I put the style.css in /Vendor/Module/view/frontend/web/css

I thought that in this case the css file could be visible ONLY in the module, but it is not.
How can I make it visible ONLY in that phtml file?
I mean, I want the css to be able to edit ONLY the files into the module.

Is it possible?

Thanks