我正在尝试在网站上制作一个模式框，但没有显示。模式框中的内容很好，但是如果需要，在这里我还要附加内容的CSS代码。
document.getElementById('buttonL').addEventListener("click", function() {
document.querySelector('.bg-modal').style.display = "flex";
});
document.querySelector('.close').addEventListener("click", function() {
document.querySelector('.bg-modal').style.display = "none";
});.bg-modal{
background-color: rgba(0, 0, 0, 0.5);
width: 100%;
height: 100%;
position: fixed;
display: none;
justify-content: center;
align-items: center;
bottom: 0px;
}
.modal-content{
width: 600px;
height: 300px;
background-color: white;
opacity: 1;
border-radius: 2px;
}
.modal-content h1{
align-items: center;
text-align: center;
margin-top: 40px;
font-family: 'Rubik', sans-serif;
}
.modal-content img{
float: left;
width: 160px;
margin-top: 20px;
margin-left: 60px;
}
.modal-content p{
float: right;
margin-top: 20px;
margin-right: 60px;
font-size: 16px;
}
.close {
position: relative;
float: right;
margin-right: 8px;
font-size: 32px;
color: #333;
background-color: none;
cursor: pointer;
}<button id="buttonL" class="buttonLegal">LEGAL DETAILS</button>
<div class="bg-modal">
<div class="modal-content">
<div class="close">✖</div>
<h1>LEGAL DETAILS</h1>
<img src="someimagehere.jpg">
<p>some text here</p>
</div>
</div>我已经搜索了整个互联网，并尝试了许多方法，但仍然无法显示模式框。我认为我的JavaScript代码可能有误，但不确定。因此，希望您能在这件事上对我有所帮助。谢谢！
您可以尝试从https://www.w3schools.com/获得此简单的模态代码
<!DOCTYPE html>
<html lang="en">
<head>
<title>Bootstrap Example</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.0/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.0/js/bootstrap.min.js"></script>
</head>
<body>
<div class="container">
<h2>Modal Example</h2>
<!-- Trigger the modal with a button -->
<button type="button" class="btn btn-info btn-lg" data-toggle="modal" data-target="#myModal">Open Modal</button>
<!-- Modal -->
<div class="modal fade" id="myModal" role="dialog">
<div class="modal-dialog">
<!-- Modal content-->
<div class="modal-content">
<div class="modal-header">
<button type="button" class="close" data-dismiss="modal">×</button>
<h4 class="modal-title">Modal Header</h4>
</div>
<div class="modal-body">
<p>Some text in the modal.</p>
</div>
<div class="modal-footer">
<button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
</div>
</div>
</div>
</div>
</div>
</body>
</html>