I have been trying to figure out how to make this plugin only run on .css files, and exclude .scss files. I thought I could accomplish this by setting extensions: ['.css'], but this still runs on the .scss files. How can I exclude files?

The reason I want to run rollup-plugin-sass on the scss and rollup-plugin-postcss on the css is because I want to inject some third party css into the head, but I want to create separate css theme files from my scss as well. If that is possible here, I could just use one plugin, but I cannot figure it out.