How can in achieve full background smoke effect in Javascript or CSS
<p>im trying to use this code:</p>

<p><a href="http://codepen.io/MIML/pen/iBKyC" rel="nofollow">http://codepen.io/MIML/pen/iBKyC</a></p>

<pre><code>canvas {
    position:absolute;
    margin-left : 50%;
    left: -150px;
}
</code></pre>

<p>To put some smoke at the bottom of my page, but im searching how can i put it using 100% width! </p>

<p>You know, all the bottom of my page, spreads smoke.</p>

<p>Thanks.</p>