It works for me in Chrome on my iPhone. Have you tried another browser on your Android device to see if you get a different result?
Also, I would remove that huge CSS reset and start with more basic CSS. That makes things like this easier to debug. How about starting with: http://jsfiddle.net/mb8Db/1/
<style>
body {
font-family:"Century Gothic", helvetica, arial, sans-serif;
font-size: 1.4em;
line-height: 1.5;
}
/* failing on Android */
body > main > article {
font-size:1em;
}
body > main > article p {
font-size:0.75em;
}
</style>
<main>
<h3>Header</h3>
<article>
<header>
<h3>Title</h3>
</header>
<p>Paragraph</p>
</article>
</main>