现场演示：我的 HTML 文档

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Creating Custom Template for Bootstrap Tooltips Using JavaScript</title>
<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.0.2/dist/css/bootstrap.min.css" rel="stylesheet">
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap-icons@1.5.0/font/bootstrap-icons.css">
<script src="https://cdn.jsdelivr.net/npm/bootstrap@5.0.2/dist/js/bootstrap.bundle.min.js"></script>
<style>
    .bs-example{
        margin: 150px;
    }
  	/* Styles for custom tooltip template */
    .tooltip-head{
        color: #fff;
        background: #000;
        padding: 10px 10px 5px;
        border-radius: 4px 4px 0 0;
        text-align: center;
        margin-bottom: -2px; /* Hide default tooltip rounded corner from top */
    }
    .tooltip-head h3{
        margin: 0;
        font-size: 18px;
    }
  	.tooltip-head i{
        font-size: 22px;
        vertical-align: bottom;
    }
</style>
<script>
document.addEventListener("DOMContentLoaded", function(){
    var element = document.getElementById("myTooltip");
    var tooltip = new bootstrap.Tooltip(element, {
        template: '<div class="tooltip" role="tooltip"><div class="tooltip-arrow"></div><div class="tooltip-head"><h3><i class="bi-info-circle"></i> Important Info</h3></div><div class="tooltip-inner"></div>'
    });
});
</script>
</head>
<body>
<div class="bs-example"> 
    <p>
        <a href="#" id="myTooltip" data-bs-toggle="tooltip" title="This is a simple example of custom Bootstrap tooltip.">Hover over me</a>
    </p>
</div>
</body>
</html>