<!DOCTYPE html>
<html>
<head>
<link rel="stylesheet" href="style.css">
</head>
<body>
<div class="container">
<iframe id="left-column" class="column">
</iframe>
<div id="right-column" class="column">Cột phải</div>
</div>
<script src="script.js"></script>
</body>
</html>
.container {
display: flex;
justify-content: space-around;
}
.column {
width: 45%;
border: 2px dashed #ccc;
padding: 10px;
}
.item {
border: 1px solid #333;
padding: 20px;
margin-bottom: 10px;
cursor: grab;
background-color: #f9f9f9;
}
let iframe = document.getElementById("left-column");
let doc = iframe.contentDocument || iframe.contentWindow.document;
doc.open();
doc.write("<h2>Nội dung được gán bằng JavaScript</h2><p>Xin chào!</p>");
doc.close();