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
The best solution for me was to add the styles to the angular.json file. Dont forget to stop your project and ng serve again after the changes:
"styles": [ "src/styles.scss", "node_modules/primeng/resources/themes/saga-blue/theme.css", "node_modules/primeng/resources/primeng.min.css" ],