<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Document</title>
<link rel="stylesheet" href="main.css">
</head>
<body>
<div class="alert-box" id="alert">Alert 박스
</div>
<button onclick="document.getElementById('alert').style.display = 'block'; ">버튼</button>
<script>
</script>
</body>
</html>
