<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>Animation of font-weight</h1>
<p>Gradually change the font-weight from normal to bold, and back to normal:<p>
<div id="myDIV">
<p>This is a paragraph</p>
</div>
</body>
</html>