title: How to make button's "pushed" effect?
body: <p>I have 3 buttons that represents 3 states. I'd like when I push some of them that button stays in visual "push" state and other 2 are in normal non-pushed state.</p>
  
  <p>Here's the code I use:</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>if (itemType === 'default') {
    document.getElementById("defaultMode").classList.remove('non-pushed');
    document.getElementById("defaultMode").classList.add('pushed');
  }</code></pre>
  <pre class="snippet-code-css lang-css prettyprint-override"><code>.pushed {
    border-style: inset;
  }
  
  .non-pushed {
    border-style: solid;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;button id="defaultMode" class="non-pushed" onclick="setMode('link', 'default');"&gt;Default&lt;/button&gt;
  &lt;button id="orthoMode" onclick="setMode('link', 'ortho');"&gt;Ortho&lt;/button&gt;
  &lt;button id="cornerMode" onclick="setMode('link', 'corner');"&gt;Corner&lt;/button&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p>But, it's not working.</p>