<!DOCTYPE html>
<html>
<head>
<title>CSS3 Advanced</title>
<meta name='viewport' content='width=device-width, initial-scale=1.0, maximum-scale=1.0' />
<link rel="stylesheet" href="styles.css">
</head>
<body>
<header id="main-header">
<h1>This is a Heading</h1>
</header>
<main class="container">
<article class="box">
<h2>Article</h2>
<p>This is a paragraph.</p>
</article>
<article class="box">
<h2>Article</h2>
<p>This is a paragraph.</p>
</article>
<form class="box">
<h2>Form</h2>
<p>First name</p>
<input type="text">
<p>Last name</p>
<input type="text">
<input type="submit">
</form>
<article class="box">
<h2>Advertisement</h2>
<p>
This is some ad text to scam u into buying <br>
our <strong><i>product</i></strong>
</p>
<p>Buy now? <input type="checkbox"></p>
</article>
</main>
</body>
</html>