<!DOCTYPE html>
<html>
<head>
<style>
#main {
width: 350px;
height: 100px;
border: 1px solid #c3c3c3;
display: flex;
}
#main div {
flex-grow: 0;
flex-shrink: 0;
flex-basis: 40px;
}
#myBlueDiv {
animation: mymove 5s infinite;
-webkit-animation: mymove 5s infinite; /* Chrome, Safari, Opera */
}
/* Chrome, Safari, Opera */
@-webkit-keyframes mymove {
50% {flex-basis: 200px;}
}
/* Standard syntax */
@keyframes mymove {
50% {flex-basis: 200px;}
}
</style>
</head>
<body>
<p>Gradually change the flex-basis property of the "blue DIV" from 40px, to 200px, and back:<p>
<div id="main">
<div style="background-color:coral;">Red DIV</div>
<div style="background-color:lightblue;" id="myBlueDiv">Blue DIV</div>
</div>
<p>The flex property is <em>animatable</em> in CSS.</p>
<p><b>Note:</b> CSS Animations do not work in Internet Explorer 9 and earlier versions.</p>
</body>
</html>