試一試 - CSS Reference anim

<!DOCTYPE html>
<html>
<head>
<style>
#myDIV {
   width: 300px;
   height: 200px;
   border: 1px solid black;
   -webkit-animation: mymove 5s infinite; /* Chrome, Safari, Opera */
   animation: mymove 5s infinite;
}

/* Chrome, Safari, Opera */
@-webkit-keyframes mymove {
   50% {border-right: 15px solid lightblue;}
}

/* Standard syntax */
@keyframes mymove {
   50% {border-right: 15px solid lightblue;}
}
</style>
</head>
<body>

<p>Gradually change the border-right property:<p>
<div id="myDIV"></div>

<p>The border-right is a shorthand property for all border-right properties.</p>
<p>See individual border-right properties to see which is <em>animatable</em>.</p>
<p><b>Note:</b> CSS Animations do not work in Internet Explorer 9 and earlier versions.</p>

</body>
</html>