Mona is a theme, usable in Grav.
On Ubuntu, do
apt-get install nodejs nodejs-legacy npm
This will give you npm package manager. You will need grunt-cli. You can install it via npm.
npm install -g grunt-cli
Now you need to install Sass
apt-get install ruby gem install sass
After, you can do first step installing Mona.
cd /mona npm install
Finally do
grunt
this will install google fonts and generate nescesary css files.
After this, Mona is ready to use.
Enjoy.
__ Leonard Siebeneicher