:host styles not rendering

[sclearion]

Following the exact instructions on the 'Step 2: Creating your own element' page of the main site, any styles defined in the :host tag do not render at all. Code using is shown below:

:host {
display: block;
position: relative;
background-color: white;
padding: 20px;
width: 100%;
font-size: 1.2rem;
font-weight: 300;
}

The code above does not change the background color to white or apply the padding. How can I work around this?

[sclearion]

had wrong version of polymer installed via bower