Questions about transferring data to parse

Now I'm using parse to generate pages, and I attach an array with it, like the following:

Code:

    private $data = array(
        'title'       => 'this is a title',
        'keywords'    => 'this is keywords',
        'description' => 'this is description',
        'css'         => array
        (
            'test'=>'ok',
            'time'=>'now'
        )
    );

As you can see, $data is an array and one of its element, css, is also an array. 
In the template I can use {title} to refer to 'title' element in $data, but how to use css array in view?

Like {css:test} ? It doesn't work.