How do I modify the width of a TabContainer in Dojo

Question

I'm experimenting with Dojo, so far it's very cool except for the fact that I can't seem to be able set the width of a TabContainer. I have the following code

<div id="tabs" dojoType="dijit.layout.TabContainer" doLayout="false">
    <div id="javaTab" class="myTab" dojoType="dijit.layout.ContentPane" title="Java">
        <h1>Hello I'm the Java Tab</h1>
    </div>
    <div id="rubyTab" class="myTab" dojoType="dijit.layout.ContentPane" title="Ruby">
        <h1>Hello I'm the Ruby Tab</h1>
    </div>
</div>

This are the CSS:

#tabs {
width: 100%;
height: 100%;
}
.myTab {
height: 600px;
width: 100%;
padding: 0 !important;
}

If I put a menu bar inside the the tabs then I find that their width is larger than my screen so I don't see the complete bar. So is there a way to set the width of the generated "tab bar"?

Thanks guys!