<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>回到顶部</title>
<style type="text/css">
body {
box-sizing: border-box;
margin: 0;
padding: 0;
}
.contaniner {
position: relative;
display: grid;
place-items: center;
}
.btn {
bottom: 10px;
right: 10px;
position: fixed;
border: 0;
outline: 2px solid lightgreen;
}
</style>
</head>
<body>
<div class="contaniner">
<div class="btn" onclick="goTop()">
<button>回到顶部</button>
</div>
<h1>下滑菜单</h1>
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<script type="text/javascript">
function goTop() {
window.scrollTo({
top: 0,
behavior: "smooth"
});
}
</script>
</div>
</body>
</html>
