To achieve a better user experience for your site, we delay the loading of jQuery. To use jQuery in custom code, you must use _strk.
Instead of placing your jQuery code directly in the header or footer, you must subscribe to the page load event and then run the code there:
<script>
_strk.push('Page.didMount', function(){ /* your jQuery code goes here */ })
</script>
The full custom code should look something like this:
<script>
_strk.push('Page.didMount', function(){
$(".s-section-1 h1").text(Math.random())
})
</script>
On the other hand, if you do not use _strk, this code will NOT work:
<script>
/* This jQuery code will NOT work */ $(".s-section-1 h1").text(Math.random()) </script>
Note: _strk works in both site custom code and blog custom code.