​x
 
<!DOCTYPE html>
<html>
<head>
<style> 
#myDIV {
  border: 1px solid black;
  width: 400px;
  height: 100px;
  animation: mymove 5s infinite;
}
​
@keyframes mymove {
  50% {font-weight: bold;}
}
</style>
</head>
<body>
​
<h1>font-weight 的动画效果：</h1>
​
<p>逐渐将字体粗细从正常更改为粗体，然后再恢复为正常：<p>
<div id="myDIV">
<p>This is a paragraph</p>
</div>
​
<p><b>注释：</b>CSS 动画在 Internet Explorer 9 以及更早版本中不起作用。</p>
​
</body>
</html>
​