ชุมนุมคอมพิวเตอร์

<!DOCTYPE html>
<html>
<head>
<title>Bouncing Ball</title>
<style>
body {
background-color: #f0f0f0;
display: flex;
justify-content: center;
align-items: center;
height: 100vh;
overflow: hidden;
}
.ball {
font-size: 50px;
position: absolute;
animation: bounce 1s infinite alternate;
}
@keyframes bounce {
0% { transform: translateY(0); }
100% { transform: translateY(-100px); }
}
</style>
</head>
<body>
<div class=”ball”>⚽</div>
</body>
</html>