title: How to make a round checkbox with angular-material
body: <p>My code is pretty simple</p>
  
  <pre><code>&lt;mat-checkbox
    [(ngModel)]="checked"
    [color]="'primary'"
  &gt;&lt;/mat-checkbox&gt;
  </code></pre>
  
  <p>How can I make this material checkbox round? I have tried setting the style <code>border-radius: 50%</code>on pretty much all tags generated by Angular under this element but the most I have achieved is a round 'selected' look inside a rectangle.</p>
  
  <p>I am sure there is a better way. I have found <a href="https://stackoverflow.com/questions/54332350/how-to-make-a-circle-checkbox-with-material-ui">this answer about reusing the graphics of a radio-button</a> but I have been unable to adapt it to my case (dont even know where to start)</p>