The application comes pre-configured with Tailwind CSS and shadcn/ui; a set of open-source, accessible components built with Radix and Tailwind. It comes with a CLI that can be used to easily add components to your application. You can see the template comes with two components made this way already, button and checkbox. From the application directory, run the following command to add a new component: 
yarn add-component
This will ask you which component(s) from all the available components you would like to add. You can add as many as you like, and they will be added to the components directory; where they become fully customizable.