How do I remove the white margins around my div tags?
<p>So I have been creating a very basic website with a <code>header</code>, <code>nav</code>, main container, and a <code>footer</code>. and I'm using the the <code>viewport</code> tag in my website.</p>

<p>My problem occurs when I set the <code>width</code> of the <code>div</code>s to <code>100%</code>.</p>

<p>Here is my code:</p>

<pre class="lang-css prettyprint-override"><code>#header {
  background-color: black;
  color: white;
  text-align: center;
  padding: 5px;
}
#nav {
  line-height: 60px;
  background-color: #FFFFFF;
  min-height: 60px;
  width: 100%;
  left: 0px;
  text-decoration: none;
}
#nav a {
  font-family: sans-serif;
  font-size: 25px;
  text-decoration: none;
  float: left;
  margin-left: 10px;
}
#section {
  min-width: 50%;
  min-height: 479px;
  float: left;
}
#section p {
  font-family: sans-serif;
  font-size: 20px;
}
#footer {
  background-color: black;
  color: white;
  clear: both;
  text-align: right;
  line-height: 40px;
  height: 40px;
}
#footer p {
  margin-right: 30px;
}
</code></pre>

<p>Is there something I need to change to get rid of the white edges around the div, I have tried things to get rid of it but none of them seem to work, any help would be greatly appreciated.</p>