title: CSS : absolute positioning of a button in Firefox
body: <p>I want to display a button which takes all spaces of its parent which is himself absolute positioned.</p>
  
  <p>But it seems that Firefox has a bug with it (All runs perfectly in Chrome and Safari (Webkits), I can't test on IE because I'm on mac (if anyone can test and say in comment if it runs or not, it would be really nice)).</p>
  
  <p>The goal to achieve is : </p>
  
  <p><img src="https://i.stack.imgur.com/6z2bx.png" alt="enter image description here"></p>
  
  <p>Div and button are together contained by a wrapper which is absolute positioned.</p>
  
  <p>The HTML code is : </p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html&gt;
      &lt;head&gt;
          &lt;style type="text/css"&gt;
              .wrapper {
                  background-color: red;
                  position: absolute;
                  width: 100px;
                  height: 100px;
              }
  
              .inner {
                  background-color: blue;
                  position: absolute;
                  top: 0px;
                  bottom: 0px;
                  left: 0px;
                  right: 0px;
              }
          &lt;/style&gt;
      &lt;/head&gt;
      &lt;body&gt;
          &lt;div class="wrapper" style="top: 50px; left: 50px;"&gt;
              &lt;div class="inner"&gt;div&lt;/div&gt;
          &lt;/div&gt;
  
          &lt;div class="wrapper" style="top: 50px; left: 200px;"&gt;
              &lt;button class="inner"&gt;button&lt;/button&gt;
          &lt;/div&gt;
      &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>That's quite simple. The problem is that on Firefox, it renders like this : </p>
  
  <p><img src="https://i.stack.imgur.com/QSjHH.png" alt="enter image description here"></p>
  
  <p>Have you got any idea why Firefox renders this code like this and have you got any workaround using similar positioning ?</p>
  
  <p>EDIT : I can't (and I don't want) set width and height on inner child. The reason is that I use GWT with layout mechanisms. GWT layout uses bottom/top/left/right to position and size elements, so I can't change this behavior. All runs with classic div. The problem is only button related. </p>