<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>心跳</title>
<style type="text/css">
/*心跳*/
div {
width: 100px;
height: 100px;
background-color: pink;
margin: 100px auto;
animation: heart 0.5s infinite; /*每隔5s执行动画，无限次*/
}
@keyframes heart {
0% {
transform: scale(1);
}
50% {
transform: scale(1.1);
}
100% {
transform: scale(1);
}
}
</style>
</head>
<body>
<div></div>
</body>
</html>