title: Angular Material 2 : mat-button css to look like mat-button-toggle
body: <p>I need help in css to obtain a <a href="https://material.angular.io/components/button/examples" rel="nofollow noreferrer">Button</a></p>
  
  <pre><code>&lt;button mat-icon-button&gt;
      &lt;mat-icon&gt;format_align_left&lt;/mat-icon&gt;
  &lt;/button&gt;
  </code></pre>
  
  <p>Equivalent (in design) to a <a href="https://material.angular.io/components/button-toggle/examples" rel="nofollow noreferrer">Button toggle</a></p>
  
  <pre><code>&lt;mat-button-toggle-group&gt;
    &lt;mat-button-toggle&gt;
      &lt;mat-icon&gt;format_align_left&lt;/mat-icon&gt;
    &lt;/mat-button-toggle&gt;
  &lt;/mat-button-toggle-group&gt;
  </code></pre>
  
  <p>Because in a real toolbar (see button toggle for example), some of the command (eg : indent) are not toggled but just clicked.</p>
  
  <p>But i don't find the exact css to apply on my button... </p>
  
  <p>Thank you for your help !</p>