Color Contrast

A wireframe is a low-fidelity visual representation of a user interface that outlines structure, layout, and content hierarchy without detailed styling or colors. Wireframes focus on what elements appear on a page and how they are arranged, serving as a blueprint before visual design begins. They help teams align on functionality and user flow early in the process, when changes are cheapest to make.

Dark mode is a UI color scheme that uses light-colored text and elements on a dark background. It reduces eye strain in low-light environments, can save battery on OLED screens, and has become an expected feature in modern applications. Implementation typically involves CSS custom properties or design tokens that switch between light and dark theme values, often respecting the user's system-level preference via the `prefers-color-scheme` media query.

The Virtual DOM is a lightweight in-memory representation of the actual browser DOM that React uses to optimize UI updates. When state changes, React creates a new Virtual DOM tree, compares it with the previous one through a process called reconciliation, and calculates the minimal set of real DOM mutations needed. This batching and diffing approach avoids expensive direct DOM manipulation and was a key innovation that made React's declarative programming model performant.

Responsive design is an approach to web development where layouts, images, and UI elements adapt fluidly to different screen sizes and devices. It relies on flexible grids, media queries, and relative units like `rem`, `%`, and `vw` to ensure a consistent experience from mobile phones to large monitors. Modern responsive design increasingly uses CSS Container Queries and intrinsic sizing techniques to create components that respond to their own container rather than the viewport.

Figma is a browser-based collaborative design tool used for creating UI designs, prototypes, and design systems. Its real-time multiplayer editing, component system, auto layout, and dev mode have made it the industry standard for product design. Developers use Figma to inspect designs, extract CSS values, export assets, and — through plugins and APIs — automate the design-to-code workflow.

A modal (or modal dialog) is a UI element that overlays the main content to demand user attention and interaction before they can return to the underlying page. Modals are used for confirmations, forms, alerts, and content previews. Proper implementation requires focus trapping, keyboard accessibility (Escape to close), and preventing background scroll — making accessible modals more complex than they appear.