How to add separator between default and custom panels in WordPress customizer?

I have implemented theme options using WordPress customizer with a mix of native WordPress customizer fields and Kirki framework. This works great.

Now, I wonder if it is possible to add a separator between my theme options and default WordPress customizer options. Something similar to the attached image.

Guess, this can be achieved by overriding custom CSS. But a native and cleaner approach is what I am looking for.