I'm using Google Web Fonts and I'm not entirely sure how to correctly define `font-style`/`font-weight`.

What is the difference in defining `normal` or `400` as the desired font-weight for regular body copy?

Do I just define `font-style: italic;` or reference an italic font-face?

**Code:**

```
<link href="http://fonts.googleapis.com/css?family=Gudea:400,700,400italic">
<style>
body {
    font: 1.25em/1.5 Gudea, Helvetica, Arial, sans-serif;
}
em {
    font-style: italic;

    /* or:
    font-style: normal;
    font-family: "Gudea Italic";
    */
}
strong {
    font-weight: bold;

    /* or:
    font-weight: 700;
    */
}
</style>

```