CSS Fundamentals and Layouts Questions

Covers core Cascading Style Sheets concepts and modern layout systems. Candidates should understand selectors, specificity, the cascade, inheritance, and the box model so they can read and reason about style rules. Expect positioning techniques including relative, absolute, fixed, and sticky, and responsive sizing units such as pixels, rem, em, and percentages plus media queries for breakpoints. Deep knowledge of Flexbox is required: when to use one dimensional layouts, key properties such as flex-direction, justify-content, align-items, gap, flex-basis, flex-grow, and flex-shrink, and practical patterns for centering and distributing space. Deep knowledge of Grid is required: two dimensional grid concepts, grid-template-columns and grid-template-rows, grid-auto-flow, grid-gap, explicit and implicit tracks, placement with grid-column and grid-row, and when Grid is preferable to Flexbox. Candidates should also be able to combine Flexbox and Grid effectively, debug layout problems, and explain trade offs for responsive and accessible layouts.