CUBE CSS is a modern CSS architecture methodology designed to create scalable, maintainable, and performance‑focused stylesheets. The acronym stands for Composition, Utility, Block, and Exception.

Accessibility ensures that websites and digital systems can be used by people with disabilities, including those who rely on assistive technologies such as screen readers, keyboard navigation, and alternative input devices.

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: