All the Drupal 8 Design and Layout Classes
Twig is a very powerful template engine for PHP. Twig is safe, fast, easy-to-learn and is used by many different platforms.
Paragraphs is an increasingly popular module for handling content in Drupal 8. Paragraphs works in a similar way to content fields, but also provides a wide range of options for the design, layout and grouping of your content.