CSS Architecture
Responsive CSS: From Mobile-First Design to Modern Styling Responsive design is about creating websites that work well across mobile, tablet, and desktop screens. In this post, I learned some important techniques for building responsive and maintainable CSS. 1. Mobile-First Media Queries Mobile-first means writing the base CSS for smaller screens first and then enhancing the layout for larger screens. /* Mobile */ .card { width : 100% ; } /* Tablet */ @media ( min-width : 768px ) { .card { width : 70% ; } } /* Desktop */ @media ( min-width : 1024px ) { .card { width : 50% ; } } The main idea is: Mobile → Tablet → Desktop min-width is commonly used for mobile-first development because styles are progressively added as the screen gets larger. min-width vs max-width min-width : applies styles when the screen is at least the specified width. max-width : applies styles when the screen is at most the specified width. For example: @media ( max-width : 768px ) { h1 { font-size : 20px ; } } One important lesson I learned: CSS media queries belong inside <style> or a CSS file, not inside <script> . 2. Fluid Typography Fixed font sizes don't always work well across different screen sizes. Fluid typography allows text to adapt to the viewport. rem rem is relative to the root font size. h1 { font-size : 2rem ; } If the root size is 16px, 2rem is 32px. vw vw is relative to the viewport width. h1 { font-size : 5vw ; } However, using only vw can make text too small or too large. clamp() clamp() provides a minimum, flexible value, and maximum: h1 { font-size : clamp ( 1.5rem , 4vw , 3rem ); } This allows the font size to grow smoothly while keeping it within limits. 3. Responsive Images Images can consume a lot of bandwidth, so responsive images help browsers choose an appropriate image for the device. srcset <img src= "small.jpg" srcset= " small.jpg 400w, medium.jpg 800w, large.jpg 1200w" sizes= "100vw" alt= "Mountain" > srcset provides multiple image sizes, allowing the browser to