css-modern

Container queries allow you to implement responsive designs based on a container's size rather than the viewport. You can style components dynamically by querying the dimensions of their parent elements, enabling truly modular and encapsulated responsive layouts.

The :has() pseudo-class is a modern CSS feature that lets you style parent elements based on their children's state. It functions as a parent selector, allowing conditional styling when a descendant element matches a specified criteria.

The @layer rule organizes CSS cascade layers for better specificity management. By declaring layers, you can control the order in which styles override each other, preventing specificity wars and making your styling architecture more maintainable.

Native CSS nesting allows you to write CSS in a hierarchical structure without preprocessors. You can nest selectors inside other selectors to group related styles, improving readability and maintaining a clean, organized stylesheet architecture.

Fallback strategies for modern CSS involve providing alternative styles for unsupported browsers. You can use feature queries like @supports to detect compatibility and apply progressive enhancement, ensuring core functionality remains accessible across different environments.

Custom properties, or CSS variables, are defined to enable dynamic styling and theming. You declare them using custom property notation and reference them throughout your stylesheet, allowing you to update values globally or scope them to specific components.