title: HTML Background color not filling whole page?
body: <p>Hey everyone here's a picture of the problem:</p>
  
  <p><img src="https://i.stack.imgur.com/ArxKH.png" alt="enter image description here"></p>
  
  <p>I want it to fill the the whitespace on the left right and top of the green box.</p>
  
  <p>HTML: </p>
  
  <pre><code>&lt;!DOCTYPE HTML&gt;
  &lt;html&gt;
      &lt;head&gt;
          &lt;LINK href="style.css" rel="stylesheet" type="text/css"&gt;
          &lt;link href='http://fonts.googleapis.com/css?family=Montserrat:700' rel='stylesheet' type='text/css'&gt;
          &lt;title&gt;Test page&lt;/title&gt;
      &lt;/head&gt;
      &lt;body&gt;
      &lt;div id="container" name="header"&gt;
          &lt;h1&gt;Blegh&lt;/h1&gt;
              &lt;style&gt;
                  #container {font-family: 'Montserrat', sans-serif;}
              &lt;/style&gt;
       &lt;/div&gt;
      &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>CSS:</p>
  
  <pre><code>#container{
      background-color: #58FA58;
      margin-left: auto;
      margin-right: auto;
      text-align: center;
      height: 100px;
      width: 100%;
  }
  </code></pre>