Untitled

<section><h1>H1 tag in a section tag</h1></section>
<article><h1>H1 tag in an article tag</h1></article>
<h1>H1 tag in nothing</h1>

:-webkit-any(article,aside,nav,section) h1 {
font-size: 1.5em;
-webkit-margin-before: 0.83em;
-webkit-margin-after: 0.83em;
}

h1 {
display: block;
font-size: 2em;
-webkit-margin-before: 0.67em;
-webkit-margin-after: 0.67em;
-webkit-margin-start: 0px;
-webkit-margin-end: 0px;
font-weight: bold;
}

<!DOCTYPE html>
<html>
    <head>
        <title>Page Title</title>
    </head>
    <body>
        <section><h1>H1 tag in a section tag</h1></section>
        <article><h1>H1 tag in an article tag</h1></article>
        <h1>H1 tag in nothing</h1>
    </body>
</html>