試一試 - CSS Reference js_animation-fill-mode

<!DOCTYPE html>
<html>
<head>
<style> 
div {
    width: 100px;
    height: 100px;
    background: red;
    position: relative;
    -webkit-animation: mymove 2s 1;  /* Chrome, Safari, Opera */
    animation: mymove 2s 2;
}

/* Chrome, Safari, Opera */
@-webkit-keyframes mymove {
    from {left: 0px;}
    to {left: 200px;}
}

@keyframes mymove {
    from {left: 0px;}
    to {left: 200px;}
}
</style>
</head>
<body>

<p>Click the "Try it" button to let the DIV element keep the styles set by the last keyframe: to {left:200px;}, when the animation is finished.</p>
<button onclick="myFunction()">Try it</button>

<p><strong>Note:</strong> For Firefox users: be sure to click the button before the animation has finished, if not the change will not have any affect because the animation will not start over once it has finished.</p>
<p><strong>Note:</strong> The animationFillMode property is only supported in Firefox.</p>
<div id="myDIV"></div>

</body>
</html>