23-05-2026 Second Mock Interview title: "Technical Interview Prep: Core HTML & CSS Concepts" published: false description: "Quick breakdown of essential web development concepts covering units, semantics, selectors, and Flexbox layout from my second mock interview." tags: webdev, beginners, css, html Sharing my notes from my second mock interview! Here is a quick breakdown of essential web development concepts. 1. Units: px vs vh The main difference lies in whether the unit is fixed or fluid . px (Pixel) : An absolute, fixed unit representing the smallest digital image point. vh (Viewport Height) : A relative unit based on the browser window height. Quick Reference 200px stays exactly 200 pixels wide on mobile, laptop, or 4K monitors. 1vh = 1% of the current viewport height. 100vh = 100% of the viewport height (fills the full screen vertically). 2. Structure: <footer> vs <div> The core difference here is Semantics (meaning). <div> (Division) : A generic, non-semantic block element.…