Revert "background index change"

This reverts commit 922fe9ce1c9da6b508948d583efa594b244ff373.
Revert "Revert "background index change""

This reverts commit af746d2cef66aa8d32081d7c656c239819b41335.
Revert "Revert "Revert "background index change"""

This reverts commit a33ff22b727bfe163ea4e47b27308554aa9b985f.
Revert "Revert "Revert "Revert "background index change""""

This reverts commit 0b3c7e04128a614881f77e130b54d975d461fb90.