How to manage rails style.css and style.scss both present in rails project

Question

Hi My I am using the Rails 5.2.1
ruby 2.4.0
I have style.scss and style.css both files present in the rails project.
The application is working fine on the Development environment.
But in the production on Nginx server after precompiling the assets by

rake assets: precompile   

The application view is distorted and browsers is giving 404 style.css not found error.
please update how to manage this kind of situation in assets when both .css and scss both are preset, or should I paste the content of style.css file in end of the style.scss file.