CSS animation-duration Property - Playground Example

<!DOCTYPE html><html><head><style type="text/css">.example {
  font-family: Arial, sans-serif;
  padding: 20px;
}

.example h2 {
  margin: 0 0 12px 0;
  font-size: 18px;
}

.boxes {
  display: flex;
  gap: 12px;
  align-items: center;
}

.box {
  width: 80px;
  height: 80px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #ffffff;
  border-radius: 8px;
  background: #3b82f6;
  animation-name: float;
  animation-duration: 2s; /* default duration */
  animation-iteration-count: infinite;
  animation-timing-function: ease-in-out;
}

.box.fast {
  background: #ef4444;
  animation-duration: 1s; /* faster */
}

.box.slow {
  background: #10b981;
  animation-duration: 4s; /* slower */
}

@keyframes float {
  0% {
    transform: translateY(0);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
  }

  50% {
    transform: translateY(-20px);
    box-shadow: 0 18px 30px rgba(0, 0, 0, 0.12);
  }

  100% {
    transform: translateY(0);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
  }
}
</style></head><body><div class="example">
  <h2>animation-duration Demo</h2>
  <div class="boxes">
    <div class="box normal">2s</div>
    <div class="box fast">1s</div>
    <div class="box slow">4s</div>
  </div>
</div></body></html>