Mobile-First Design is a frontend strategy where layouts, styling, and performance decisions are built for the smallest screen first and progressively enhanced for larger devices.

Twig is the core of this section.
If you master Twig:

• You gain easy points
• You avoid common traps
• You understand render flow
• You improve debugging speed

Exam mindset rule:

If question mentions:

Responsive design in Drupal 10 and Drupal 11 is not just CSS media queries. It integrates:

Layout Builder is Drupal core’s visual layout management system that allows administrators and site builders to control page structure using sections and blocks without writing custom templates.

Paragraphs is one of the most powerful contributed modules in Drupal for building flexible, component-based content structures.