The concept of Visual States is not available when building Store apps with HTML and JavaScript. The "states" pane is only available when building XAML apps (WPF, Silverlight or Windows Store XAML). In the same way the Styles, HTML property and CSS property panes are only available when working on Windows Store HTML apps.
You can use Blend to set the CSS classes for different states. You can set the current view orientation on the Device pane. Using the css media queries you can set different properties on a similar class that is used in html. You can do this the same way as you would changing other CSS properties.
I hope this screenshot explains it a little further. In this example I set a green color to the filled state and a red one to the snapped state. The media query causes one to be picked over the other.

update:
I decided to write a tutorial about the subject that goes into a bit more detail.