Question Pixel scaling in URP looking weird

Hi, I'm completely new to shaders and trying to make a 3d pixelation shader in URP. My pixels are rectangular and I don't really understand how to fix it through the shader graph. I would like for my pixels to actually be square instead of rectangular.

This is my shader graph:


Here's how my pixels look in-game (I've set the pixel scaling to 8, to further show the pixel width issue):

As you can see, my pixels are wider than their height because of the game screen's aspect ratio. Any help how to set up the shader graph to fix this would be greatly appreciated. Thanks!