<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Test Page - Iframe</title>
<style>
body { font-family: sans-serif; padding: 20px; }
iframe { border: 1px solid #ccc; width: 400px; height: 200px; }
</style>
</head>
<body>
<h1 id="main-title">Main Page</h1>
<iframe id="test-frame" name="testframe" srcdoc='
<!DOCTYPE html>
<html>
<body>
<h1 id="frame-title">Inside Frame</h1>
<button id="frame-btn">Frame Button</button>
<input id="frame-input" type="text" placeholder="Type here">
<div id="frame-result"></div>
<script>
document.getElementById("frame-btn").addEventListener("click", () => {
document.getElementById("frame-result").textContent = "Frame button clicked";
});
</script>
</body>
</html>
'></iframe>
</body>
</html>