Responsive Design and Mobile First Questions

Comprehensive understanding of responsive web design and the mobile first design approach, covering the full set of techniques used to make interfaces adapt across mobile, tablet, and desktop devices. Candidates should explain the rationale for designing mobile first and progressive enhancement, use of the viewport meta tag, and how to select and apply breakpoints. Core layout skills include fluid and flexible layouts, grid systems, and layout techniques such as Flexbox and Cascading Style Sheets Grid. Candidates should be familiar with relative sizing using percentages, em, rem, and viewport units, and with composing media queries to alter layout and behavior across viewport sizes. Important additional topics include responsive image strategies using the picture element and srcset and sizes attributes, support for high density or retina displays, touch friendly interaction patterns, accessibility considerations across devices and input types, performance implications for mobile networks, testing strategies across device sizes and browsers, and newer features such as container queries and aspect ratio controls when applicable.