web-components

To build reusable web components, define a class extending HTMLElement, register it with customElements.define, and attach a shadow DOM. This encapsulates styling and behavior for predictable, framework-agnostic UI elements across projects.

Shadow DOM encapsulation isolates a component's DOM and styles from the main document, preventing style leakage. You need it when building scalable design systems or component libraries requiring consistent, predictable rendering across different applications.

HTML templates define reusable markup chunks without rendering, while slots act as insertion points for external content. Together, they enable flexible slot-based content composition, allowing developers to assemble complex design systems from customizable parts.

Yes, you can create framework-agnostic UI components using Custom Elements registration and Shadow DOM isolation. This approach solves UI fragmentation by enabling reusable elements that behave predictably across different projects and frameworks without dependencies.

The best way to structure a universal user-card component is by attaching a shadow DOM and using slots for content composition. This allows the component to be themed and assembled with external content across various applications.

Custom elements provide a framework-agnostic way to encapsulate UI pieces, solving the fragmentation of UI across projects. Unlike framework-specific components, they enable reusable, consistent elements that behave predictably without external library dependencies.