title: Unwanted outline or border around button when clicked
body: <p>I have a styled button on my website. But when I click it, it creates an unwanted border or outline (I don't know which). How can I remove that border? Below is all the code that pertains to the button.</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="false" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>button {
      border: hidden;
      cursor: pointer;
      outline: none;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;button&gt;this is my button&lt;/button&gt;</code></pre>
  </div>
  </div>
  </p>