Can we edit the visual look of the editor

I am making a unique looking app using [blocks.css](https://thesephist.github.io/blocks.css/) as the main style. I want to have similar styles to the editor.

How can I add custom CSS/styles to it?

I want something like this :

The issue names no source file, test, or implementation entry point. Start by reviewing the editor's available styling/customization surface and the linked blocks.css reference; done means establishing whether the requested appearance is supported and documenting or scoping the required customization.

Written by the indexing model from the issue text.