Textual is developed by the author of Rich, the Python library for fancy formatting in the terminal. Is is a framework based on Rich for creating TUI apps. It is inspired by Vue.

The article points to a YouTube video https://youtu.be/bXgIj2cXaZ4, where Will shows how to style a 4-pane TUI with CSS-like configuration file. The styling also includes the ability to style based on whether a panel is active or not.

This looks really powerful. I expect to start seeing a lot more TUIs written in Python using Textual. It looks like it will be easy to quickly build a very nice terminal app with this.