小编K. *_*ven的帖子

var speed = 3;
document.getElementById("speedText").innerHTML = speed + "s";

function changeSpeed(change) {
  speed = speed + change;
  document.getElementById("speedText").innerHTML = speed + "s";
  document.getElementById("rotationDiv").style.animationDuration = speed + "s";
  $("#rotationDiv").load(location.href + " #rotationDiv");
}

#rotationDiv {
  width: 200px;
  height: 200px;
  background-color: blue;
  animation-name: spin;
  animation-duration: 3s;
  animation-iteration-count: infinite;
  animation-timing-function: linear;
}
@keyframes spin {
  from {
    transform: rotate(0deg);
  }
  to {
    transform: rotate(360deg);
  }
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="rotationDiv"></div>
<p id="speedText"></p>
<button id="button1" onclick="changeSpeed(-1)">Speed Up</button>
<button id="button2" …