Building modern CSS animations

A practical guide to mastering CSS animations: transitions, keyframes, performance best practices and accessibility tips for smooth UI motion.

CSS animations enrich the user experience without any JavaScript. ## Transitions ```css .button { transition: all 0.3s ease; } .button:hover { transform: translateY(-2px); box-shadow: 0 4px 12px rgba(0,0,0,0.2); } ``` ## Keyframes ```css @keyframes fadeIn { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } } .element { animation: fadeIn 0.5s ease-out; } ``` ## Best practices ### Performance - Animate transform and opacity - Use will-change sparingly - Avoid animating layout properties ### Accessibility - Respect prefers-reduced-motion - Keep durations reasonable (200-500ms) - Avoid flashing effects Animations should guide the user, not distract them.