<!DOCTYPE html>
<html>
<head>
<style>
#myDIV {
width: 50%;
background-color: lightblue;
overflow: auto;
border: 1px solid black;
animation: mymove 5s infinite;
}
@keyframes mymove {
50% {min-width: 800px;}
}
</style>
</head>
<body>
<h1>Animation of min-width</h1>
<p>Change the min-width from "none" to 800px, and back to "none":<p>
<p><strong>Note:</strong> The min-width property overrides the width property.</p>
<div id="myDIV">
<p>This DIV element has a pre-defined width: 50%.</p>
<p>An animation will gradually change the min-width to 800 pixels.</p>
</div>
</body>
</html>