css_basic.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
</head>
<body>
    <iframe height="600" style="width: 100%;" scrolling="no" title="Milestone-Web Dev (CSS)" src="https://codepen.io/doyoonkim3312/embed/qByqmez?default-tab=html%2Cresult&editable=true" frameborder="no" loading="lazy" allowtransparency="true" allowfullscreen="true">
        See the Pen <a href="https://codepen.io/doyoonkim3312/pen/qByqmez">
        Milestone-Web Dev (CSS)</a> by Doyoon Kim (<a href="https://codepen.io/doyoonkim3312">@doyoonkim3312</a>)
        on <a href="https://codepen.io">CodePen</a>.
      </iframe>
</body>
</html>