kanami is a GTK-based powermenu.
cargo install kanami
Copy config.toml, a sample configuration file, to ~/.config/kanami/config.toml or /etc/kanami/config.toml.
Styling is done using the CSS file format via a file named style.css.
Valid locations for this file are ~/.config/kanami/style.css or /etc/kanami/style.css.
A good starting point is style.css, the default style.