Default theme can be set using the envar DIYA_DEFAULT_THEME, this will cause the shell searching for CSS file theme in /home/$USER/.themes/<name>/gtk-4.0/gtk.css:

diya-shell: will looking for file: dev.iohub.diya.session-shell.css
diya-login-shell: will looking for file: dev.iohub.diya.login-shell.css

Virtual keyboard layout

Default virtual keyboard keymap can be set via the DIYA_VKB_KEYMAP environment variable. When created virtual keyboard, the shell will search for keymap file in: /home/$USER/.config/diya/xkb/${DIYA_VKB_KEYMAP}.keymap

Launch terminal based application

create file in /home/$USER/bin/xdg-terminal-exec with:

#! /bin/sh
foot $@

this allows gtk4-launch to launch a terminal based application