We can build interfaces looking like this:

This is the Forest ttk theme. "ttk"? Yes, for Tcl/Tk! A lightweight and cross-platform GUI toolkit (and language). It doesn't have to look outdated!

Install the nodgui library with Quicklisp, clone a theme, load it and use it:

  (with-nodgui ()
    (eval-tcl-file "ttkthemes/ttkthemes/png/yaru/yaru.tcl")
    (use-theme "yaru")

that's all there is to it.

The ttkthemes work: https://ttkthemes.readthedocs.io/en/latest/themes.html (just like with Python's Tkinter).

See more on the Cookbook and on Peter Lane's examples: https://peterlane.netlify.app/ltk-examples/

More screenshots and examples: https://github.com/vindarel/ltk-tests/, such as this toy media player: