m3ta-home/profiles/contexts/desktop/theme/theme.nix

# GTK and Qt theming — system-wide dark Adwaita/libadwaita-compatible theme.
{
  pkgs,
  config,
  ...
}: {
  qt = {
    enable = true;
    platformTheme.name = "gtk";
  };

  gtk = {
    enable = true;
    colorScheme = "dark";
    theme = {
      # Must match a directory in pkgs.adw-gtk3/share/themes.
      # "Adwaita" is not provided by this package and makes GTK4 import
      # a missing CSS file; use the explicit dark variant instead.
      name = "adw-gtk3-dark";
      package = pkgs.adw-gtk3;
    };
    iconTheme = {
      name = "Papirus-Dark";
      package = pkgs.papirus-icon-theme;
    };
    gtk4.theme = config.gtk.theme;
  };
}