title: CSS property with no value
body: <p>I'm designing a GUI for users to create web buttons. I'm wondering if it's ok to not enter a value for a CSS property?</p>
  
  <p>I've looked into inserting a property's default value if a user doesn't select one. But I run into a problem with properties that have no default value like "color". I found a reference for all CSS properties at: <a href="https://developer.mozilla.org/en/CSS/CSS_Reference" rel="nofollow">https://developer.mozilla.org/en/CSS/CSS_Reference</a></p>
  
  <p>I've tested it in the most recent versions of all 5 major browsers and it seams to work fine; but I'm not sure if that will always hold true in the future. I have considered programmically, with PHP, removing the entire property if a user doesn't choose a value for it. But I want to know what your thoughts are on using CSS properties without specifying a value before doing that?</p>
  
  <p>CSS:</p>
  
  <pre class="lang-css prettyprint-override"><code>.btn {
      background-color: #000000;
      border-color: #666666;
      border-style:;
      border-width:2px;
      color:;
  }
  </code></pre>
  
  <p><strong>EDIT</strong></p>
  
  <p>Here is my solution:</p>
  
  <p>I simply remove any CSS properties that are not defined by the user with PHP.</p>
  
  <pre><code>$css = preg_replace('/[\n\r].+:;/i', '', $css);
  </code></pre>