=== Test 1: Opacity 1 -> 0.5 (should create SC) ===
Before: opacity element has SC = false
After opacity=0.5: opacity element has SC = true

=== Test 2: Opacity 0.5 -> 0.3 (SC should persist, no rebuild needed) ===
After opacity=0.3: opacity element has SC = true

=== Test 3: Opacity 0.3 -> 1 (should remove SC) ===
After opacity=1: opacity element has SC = false

=== Test 4: Transform none -> translateX(10px) (should create SC) ===
Before: transform element has SC = false
After transform=translateX(10px): transform element has SC = true

=== Test 5: Transform translateX(10px) -> translateX(20px) (SC should persist) ===
After transform=translateX(20px): transform element has SC = true

=== Test 6: Transform translateX(20px) -> none (should remove SC) ===
After transform=none: transform element has SC = false

=== Test 7: Filter none -> blur(1px) (should create SC) ===
Before: filter element has SC = false
After filter=blur(1px): filter element has SC = true

=== Test 8: Filter blur(1px) -> none (should remove SC) ===
After filter=none: filter element has SC = false

=== Test 9: Isolation auto -> isolate (should create SC) ===
Before: isolation element has SC = false
After isolation=isolate: isolation element has SC = true

=== Test 10: Isolation isolate -> auto (should remove SC) ===
After isolation=auto: isolation element has SC = false