title: How and where to use ::ng-deep?
body: <p>I'm new to Angular 4, so could anyone please explain how and where to use <code>::ng-deep</code> in Angular 4?</p>
  <p>Actually I want to overwrite some of the CSS properties of the child components from the parent components. Moreover is it supported on IE11?</p>
  <p>Thanks for the help.</p>