<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<script src="https://code.jquery.com/jquery-2.2.4.min.js" integrity="sha256-BbhdlvQf/xTY9gja0Dq3HiwQF8LaCRTXxZKRutelT44="
crossorigin="anonymous"></script>
</head>
<body>
<div class="content">
1234
</div>
</body>
<script type="text/javascript">
//到頁面1秒後顯示
$(function() {
setTimeout(function() {
$(".content").animate({
height: "30px"
});
}, 1000)
//到頁面3秒後消失
setTimeout(function() {
$(".content").animate({
height: "0px"
});
}, 3000)
})
</script>
<style>
.content {
background: #007DDB;
height: 0px;
overflow: hidden;
}
</style>
</html>
