title: Angular 2 styling on component selector tags?
body: <p>I've been looking at a few Angular 2 frameworks, mainly Angular Material 2 and Ionic 2.  In their component stylings, there are a few styles where the CSS is put directly on the tags.  For example, for the Card component, you see styles like this:</p>
  
  <pre><code>md-card { // some styling }
  </code></pre>
  
  <p>vs</p>
  
  <pre><code>.md-card { // some styling }
  </code></pre>
  
  <p>Which would be considered a best practice?  Main reason I'm asking is because I'm working on a project where some of the components have styling on tags and others are using the classic approach.</p>
  
  <p>One benefit I could see in the elements approach is that the HTML template(s) would have less bloat -- no need for an inner  tag.  Another would be that using certain Decorators like HostBinding would be just slightly easier.</p>