<body> style.css

<header>

<article>

<h1>

<h2>

<h3>

<h4>

<h5>

<h6>

Plain Content

<p>

<div>

<li>1
<li>2

<li>1
<li>2

<blockquote> width: auto;

<pre>

<figure> width: auto;

<figcaption>

<address>

<section>

<div>
<article>、<aside>、<nav>、<section>はh1に変なuser agent stylesheetがあたる

<h1>

<h2>

<h3>