How to add static gif background to my store?

Topic summary

A user is trying to add a static GIF background to their Shopify store (sektorseven.hu), similar to the Bronze56k shop reference site.

Main Issue:

  • The GIF background displays correctly in the Shopify editor but doesn’t work properly on actual mobile devices
  • On mobile, the background moves/scrolls with content instead of remaining fixed, and appears sized incorrectly

Technical Details:

  • User implemented CSS code with background-attachment: fixed and background-size: cover
  • The desktop/editor preview shows the desired static effect
  • Mobile browser behavior differs from the editor preview

Current Status:

  • Another user requested the full CSS code to troubleshoot
  • A third participant mentioned achieving similar results but encountered a transparency issue with the cart tab
  • The discussion remains open with no definitive solution provided for the mobile display problem
Summarized with AI on November 11. AI used: claude-sonnet-4-5-20250929.

I managed it, but when I click on the cart the tab becomes transparent, if you can help me

And I wanted it to look like this site: