title: Container does not show all children panels with equal widths
body: <p>I'm new to Sencha Touch 2.</p>
  
  <p>I want to create a basic example, which has a container with 3 panels inside. But it seems that only first panel shows, two remaining are hidden. What's wrong? Here's my code:</p>
  
  <pre><code>Ext.create('Ext.Container',{
    fullscreen: true,
    layout: 'card',
    items: [
      {
        xtype: 'panel',
        html: 'first one',
      },
      {
        xtype: 'panel',
        html: 'second one',
      },
      {
        xtype: 'panel',
        html: 'third one',
      },
    ]
  });
  </code></pre>
  
  <p>If it can be done, how could I set them with equal widths?</p>
  
  <p>Thanks for any help.</p>