<h1 class="version-one">red headine</h1>
<h1 class="version-two">blue heading</h1>
<style>
.version-one {
    /* your styles for the class version-one */
    font-size: 3em;
    color: red;
}

.version-two {
    /* your styles for the class version-two */
    font-size: 3em;
    color: blue;
}
</style>

You also could use h1.version-one as the selector to ensure you’re only targetting h1-elements with this class and not other elements with this class (e.g. a paragraph).

หรือ

<style>
.version-one h1 {
    color: red;
}
.version-one h2 {
    color: orange;
}

.version-two h1 {
    color: blue;
}
.version-two h2 {
    color: purple;
}
</style>

<div class="version-one">
    <h1>lorem lipsum</h1>
    <h2>lorem lipsum</h2>
</div>

<div class="version-two">
    <h1>lorem lipsum</h1>
    <h2>lorem lipsum</h2>
</div>

http://jsfiddle.net/LDNjg/