Z-index animation property handles non-zero values incorrectly

Steps to reproduce:

1. Open the "ZIndexAnim.zip" project
2. Open the "New Animation" Animation Clip
3. Select the "New UXML" PanelRenderer in the Hierarchy
4. Enable "Preview" in Animation window
5. In the "#But" property field in Animation window, change the value to "0.01"
6. Observe the Game view

Actual results: Vertical button appears behind the horizontal

Expected results: Horizontal button appears behind the vertical

Reproducible with versions: 6000.7.0a5

Can’t test with versions: 6000.0.83f1, 6000.3.23f1, 6000.5.10f1, 6000.6.0b10, 6000.7.0a4 (No Z-index implementation)

Tested on (OS): Windows 11 Pro (25H2)

Notes:

• This property should not accept floats
• The issue occurs even when using whole numbers
• Horizontal button has the z-index of 50, and the vertical has the z-index of 100