Hi @Glasseye,
Thank you reaching out to us. This would require customization as this is not a theme feature by default and is outside of our support scope, but we will do our best to help you getting started with the customization but we will not be able to implement it.
Inspect your Navigation Dropdown element in Cornerstone and in Element CSS, paste the following code:
$el [data-x-stem*="d"] {
top: auto;
bottom: 100%;
}
Please note that since this is a custom code that changes the default behavior/display of the theme, you will be responsible to maintain or update the code in case you require further changes or if the code stops working in future updates. If you are uncertain how to proceed, it would be best to get in touch with a developer.
Thank you for understanding!