Librarian uses Twig, the Symfony template engine, to deliver front-end views.
Templates are organized into themes. To customize your views, it is best to create a custom theme based on the theme you want to be the base for your custom design.
To do that, create a copy of the theme folder in app/Resources/themes and change the templates_path in your config.php file to point to your custom theme folder.
The default themes are built with Tailwind CSS. A tailwind.config.js is included in the root of the project, as well as the package.json file to set up NPM dependencies (required if you're rebuilding the CSS assets).
Librarian comes with a default blog style theme. You can find more themes at librarianphp/librarian-themes.
Theme contributions welcome!