HC || AMP Sticky Footer CSS
https://help.instapage.com/hc/en-us/articles/360026173733-Add-a-sticky-header-or-footer-to-your-AMP
https://gist.github.com/dan-donica/1efe6ff7f01a98efe465fe8fea5df005
<!-- Begin "AMP Sticky Footer" || Help center -->
<!-- Insert in Settings->HTML/CSS->Head -->
<!-- CS:20200120-06-2 -->
<style amp-custom>
section:last-child {
position: fixed;
bottom: 0;
width: 100%;
z-index: 1000000;
}
</style>
<!-- End "AMP Sticky Footer" || Help center -->