Hard Edges On Corners I have a model with a smooth curve, and on the front of the model, I extruded the faces inwards, I trying to make the edges less curved, so they look like a rectangle. So I added support loops, which minimise the smoothness on the edges, but it alters the smoothness of the curved mesh. Is there a method to get the edges more harder?

Thank you.
Select the edges that should be sharp and use Shift+E to adjust the Edge Crease. This controls the weight used for the edge by the subdivision surface modifier. Alternatively you can also control the value in the sidebar. Open the sidebar with N > Item > Transform and change the value for Crease.