title: How does "#" (hash mark, number sign) close a modal box?
body: <p>I recently read this article about creating a pure CSS modal box:</p>
  
  <ul>
  <li><a href="http://www.webdesignerdepot.com/2012/10/creating-a-modal-window-with-html5-and-css3/gnerdepot.com/2012/10/creating-a-modal-window-with-html5-and-css3/">Creating a modal window with HTML5 &amp; CSS3</a></li>
  </ul>
  
  <p>I've tested the code and it works great. I'm using it for my site's contact and register/log-in pages.</p>
  
  <p>There is one part of the code I haven't fully grasped.</p>
  
  <p>How does this...</p>
  
  <pre><code>&lt;a href="#close" title="Close" class="close"&gt;X&lt;/a&gt;
  </code></pre>
  
  <p>...<em>close the box?</em></p>
  
  <p>There is nothing in the CSS that hides or removes an element with a <code>close</code> class, nor any similar function targeting <code>href</code>, <code>#close</code> or <code>title</code>. It's simply that one line of code by itself, and when the use clicks on it, the modal window closes (neatly and elegantly, I might add).</p>
  
  <p>It's clear that the "close" text doesn't matter. The text could be anything and the function works. But if "#" is removed, the styling fails, but the window still closes.</p>
  
  <p>So what's so special about "#"?</p>
  
  <p><div class="snippet" data-lang="js" data-hide="true" data-console="true" data-babel="false">
  <div class="snippet-code snippet-currently-hidden">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>.modalDialog {
    position: fixed;
    font-family: Arial, Helvetica, sans-serif;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    background: rgba(0, 0, 0, 0.8);
    z-index: 99999;
    opacity: 0;
    transition: opacity 400ms ease-in;
    pointer-events: none;
  }
  .modalDialog:target {
    opacity: 1;
    pointer-events: auto;
  }
  .modalDialog &gt; div {
    width: 400px;
    position: relative;
    margin: 10% auto;
    padding: 5px 20px 13px 20px;
    border-radius: 10px;
    background: #fff;
  }
  .close {
    background: #606061;
    color: #FFFFFF;
    line-height: 25px;
    position: absolute;
    right: -12px;
    text-align: center;
    top: -10px;
    width: 24px;
    text-decoration: none;
    font-weight: bold;
    border-radius: 12px;
    box-shadow: 1px 1px 3px #000;
  }
  .close:hover {
    background: #00d9ff;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;a href="#openModal"&gt;Open Modal&lt;/a&gt;
  
  &lt;div id="openModal" class="modalDialog"&gt;
    &lt;div&gt;
      &lt;a href="#" title="Close" class="close"&gt;X&lt;/a&gt;
      &lt;h2&gt;Modal Box&lt;/h2&gt;
      &lt;p&gt;This is a sample modal box that can be created using the powers of CSS3.&lt;/p&gt;
      &lt;p&gt;You could do a lot of things here like have a pop-up ad that shows when your website loads, or create a login/register form for users.&lt;/p&gt;
    &lt;/div&gt;
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>