How to make background images in sections dock?

Question

css

The site uses background images for each section, one image smoothly transitioning into another. When you set an image for each section, they don't stack (I tried background-size cover, contain, 100%, 100% auto).
Now I wrapped all the sections in a .wrapper block, combined the pictures and added a common background to the wrapper block.
At different resolutions, everything floats and does not match the layout.
Website

Answer 1

Joints between sections must be made up by separate elements.
Best of all background pictures where it is possible to make seamless textures. From the background image with the ocean, you can separately extract the luminosity channel (LAB mode in Photoshop) and blend it with the usual gradient in the luminosity mode. All this will greatly save on the size of the images and get the result close to the layout.