Tab styled navbar menu?

How can I make it so when users hover over a main nav-link, it changes the main nav-link style too appear as tab attached to the top of the dropdown of sub-nav options? And then when they mouse outside of the nav the nav hides… along with the main nav-link. The intent is to show the dropdown links are attached (visually) to the main nav-link.

Here’s an example of the style: https://cloud.netlifyusercontent.com/assets/344dbf88-fdf9-42bb-adb4-46f01eedd629/49f1202c-ad2e-489a-83d8-25276ad24540/macstorm.gif


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