Responsive Web Design Principles Responsive design ensures your website looks great and functions well on all devices, from smartphones to desktop computers. Mobile-First Approach Start designing for mobile devices first, then enhance for larger screens: /* Mobile styles (default) */ .container { width: 100%; padding: 1rem; } /* Tablet styles */ @media (min-width: 768px) { .container { max-width: 750px; margin: 0 auto; } } /* Desktop styles */ @media (min-width: 1024px) { .co...