title: CSS background cut
body: <p>this is my code, and as you can see <em>body</em> has some background image, and <em>#cont</em> should be white. But I want my <em>div</em> elements to be transparent in a way that I can see body background image. Any CSS tricks that can do that?</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-css lang-css prettyprint-override"><code>body {
    margin: 0;
    border: 0;
    padding: 0;
    height: 100%;
    width: 100%;
    background-image: url(image.png);
    background-position: center;
    background-repeat: no-repeat;
    background-size: cover;
  }
  #cont {
    margin: 0;
    border: 0;
    padding: 0;
    background-color: white;
  }
  #cont div {
    margin: 20px;
    border: 1px solid gray;
    padding: 0;
    width: 50px;
    height: 50px;
    float: left;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div id="cont"&gt;
    &lt;div&gt;&lt;/div&gt;
    &lt;div&gt;&lt;/div&gt;
    &lt;div&gt;&lt;/div&gt;
    &lt;div&gt;&lt;/div&gt;
    &lt;div&gt;&lt;/div&gt;
    &lt;div&gt;&lt;/div&gt;
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>