有什么建议可以修复这个内容抖动吗？如果我从a中删除title="1"，则元素抖动将消失。
<!DOCTYPE html>
<html lang="en">
<head>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<script type="text/javascript">
$(document).ready(function () {
$('[data-toggle="tooltip"]').tooltip();
});
</script>
</head>
<body>
<div class="container">
<div class="list-group">
<a data-toggle="tooltip" href="TEST.ASP" class="list-group-item" title="1">First item</a>
</div>
</div>
<div class="container">
TEST
</div>
</body>
</html>将页边距底部0添加到列表的第一个子项，检查以下代码：
<!DOCTYPE html>
<html lang="en">
<head>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<script type="text/javascript">
$(document).ready(function () {
$('[data-toggle="tooltip"]').tooltip();
});
</script>
</head>
<body>
<style>
.list-group-item:first-child {
margin-bottom:0;
}
</style>
<div class="container">
<div class="list-group">
<a data-toggle="tooltip" href="TEST.ASP" data-toggle="tooltip" data-placement="bottom" class="list-group-item" title="1">First item</a>
</div>
</div>
<div class="container">
TEST
</div>
</body>
</html>