CSS Animations

Transitions, keyframes, performance, and advanced animation patterns.

Overview

CSS animations create smooth, performant visual effects.

Key Concepts

• Transitions — Smooth state changes
• Keyframes — Multi-step animations
• Transform — Translate, rotate, scale
• Performance — GPU-accelerated properties
• Easing — Timing functions

Code Examples

/* Transitions */
.button {
  background: var(--primary);
  transition: all 0.3s ease;
}

.button:hover {
  background: var(--primary-dark);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

/* Keyframe animations */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes slideIn {
  from { transform: translateX(-100%); }
  to { transform: translateX(0); }
}

@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.05); }
}

.animate-fade-in {
  animation: fadeIn 0.5s ease-out forwards;
}

.animate-slide-in {
  animation: slideIn 0.3s ease-out;
}

.animate-pulse {
  animation: pulse 2s infinite;
}

/* Staggered animations */
.stagger-item {
  opacity: 0;
  animation: fadeIn 0.5s ease-out forwards;
}

.stagger-item:nth-child(1) { animation-delay: 0.1s; }
.stagger-item:nth-child(2) { animation-delay: 0.2s; }
.stagger-item:nth-child(3) { animation-delay: 0.3s; }

/* Scroll-driven animations */
@keyframes reveal {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}

.reveal-on-scroll {
  animation: reveal linear both;
  animation-timeline: view();
  animation-range: entry 0% cover 40%;
}

/* Hover effects */
.hover-lift {
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.hover-lift:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
}

/* Loading spinner */
@keyframes spin {
  to { transform: rotate(360deg); }
}

.spinner {
  width: 40px;
  height: 40px;
  border: 4px solid #f3f3f3;
  border-top: 4px solid var(--primary);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

Practice

Create a page with scroll-triggered animations and hover effects.