What is the BEM methodology in CSS?

The BEM (Block, Element, Modifier) methodology is an approach to writing CSS that helps create reusable and scalable styles.

• Block: an independent component, e.g., menu, button.
• Element: a part of a block that cannot exist independently, e.g., menu__item, button__icon.
• Modifier: a variant of a block or element that changes its appearance or behavior, e.g., button--disabled, menu__item--active.

Example of using classes according to BEM:

<div class="menu">
  <a class="menu__item menu__item--active" href="#">Home</a>
  <a class="menu__item" href="#">About</a>
</div>

This approach makes the structure easier to understand and maintain CSS, reduces the likelihood of style conflicts, and improves code readability.