Responsive Design

Responsive web design is a design approach where a website automatically adapts to the screen size of the respective device - whether desktop, tablet, or smartphone. Technically it's based on flexible grids, flexible images, and CSS media queries. Since 2015, mobile-friendliness is a Google ranking factor (Mobilegeddon), since 2018 mobile-first indexing applies. Breakpoints define at which screen width the layout changes (typical: 576px, 768px, 992px, 1200px). Best practices: Mobile-first development, touch targets at least 44×44px, readable font sizes without zoom, no horizontal scrollbars. Responsive design is standard today - separate mobile sites are outdated.