How can i blend the waves into the background?

hi guys! im very new to blender so still finding my feet. ive created this very simple gradient background with a seperate plane infront with a wave texture. i really want to blend the waves into the backround somehow to get rid of the very harsh horizontal cutoff but i dont know where to start. all of this is done in the shader editor

Screenshot 2025-11-27 150708

You can make a “Fade out” on your Plane.

Thank You!!!