Hi I just started working with angular 2. I found this library PrimeNG, I followed this tutorial: http://blog.davincisoftware.sk/primeng-web-component-framework-based-on-ang
You need to turn off encapsulation for the component.
The basic concept is that each component hides it's styles from other component so they don't overwrite each other. You can read more about encapsulation here.
...
import { ..., ViewEncapsulation } from '@angular/core';
@Component {
...
encapsulation: ViewEncapsulation.None,
} ...