z-index blocking out zoom-in zoom-out for Google map iframe
<p>I'm having a diagonal image which I will use for the complete body background. I have a large space in the image in which I've inserted the google map iframe. However it is not clickable or zoom-in or zoom-out.</p>

<pre><code>iframe {
    width: 100%;
    height: 100%;
    border: 0;
    position: fixed;
    top: 0;
    z-index: -9999999999;
}
img {
    position: fixed;
    top: 0;
}
</code></pre>

<p><a href="https://jsfiddle.net/3ef2onLc/1/" rel="nofollow noreferrer">https://jsfiddle.net/3ef2onLc/1/</a></p>