Code injection breaks mobile menu

Site URL: https://www.edtech-consultants.com/

Having an issue. I injected this widget script into the site footer, but after doing so the navigation menu on mobile is completely non-functional:

Code in footer:

<!-- Calendly badge widget begin -->
<link href="https://assets.calendly.com/assets/external/widget.css" rel="stylesheet">
<script src="https://assets.calendly.com/assets/external/widget.js" type="text/javascript" async></script>
<script type="text/javascript">window.onload = function() { Calendly.initBadgeWidget({ url: 'https://calendly.com/edtechmark', text: 'Schedule a free consultation', color: '#00a2ff', textColor: '#ffffff', branding: true }); }</script>
<!-- Calendly badge widget end -->

I tried putting this code in the header and prefooter as well, but the same problem occurs.  Does anyone have a fix?

Hi. Add this to Design > Custom CSS

/* fix mobile calendy */
@media screen and (max-width:640px) {
#sidecarNav {
    z-index: 100000 !important;
}
}

Hi tuanphan, thanks so much, that worked!