Custom rectangle gradient!

Hey guys,

I attached a screenshot to make it easier to understand: Basically its quite simple: I want that gradient starting from the middle be a rectangle, not a circle. Reason ist my navbar is completely black and i have an animation at the back going on. I dont like unclean transitions, so I thought i could add a gradient going around the viewport. May someone help me out please?

Thank you so much in advance guys! :slight_smile:

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