Change Z-Index on scroll

Hi
I hope someone can help me. The spiral Items should appear in front of the spline scene in the middle section and appear behind the spline scene in the top and lower section. How can I achieve that?

Kind Regards
Marcus


Here is my site Read-Only: **[[LINK][1]
https://preview.webflow.com/preview/weed-3b2f75?utm_medium=preview_link&utm_source=designer&utm_content=weed-3b2f75&preview=cf14a0c9f0a0fb8293eb3629f91e1ebd&pageId=653f8b0e429e7727a9b4e58a&workflow=preview

Live Link
https://weed-3b2f75.webflow.io/unserservice