[Scroll Bar]: inconsistent visibility of a bottom line across different zoom levels in modal window

[NatalliaAlieva]

Description

The bottom line of the scroll bar in modal windows doesn't always disappear when scrolling to the bottom, varying with different browser zoom levels.

Steps to Reproduce

1. Open a basic modal window example.
2. Change the browser's zoom level (try different levels such as 100%, 125%, 133%, etc.).
3. Scroll to the bottom of the modal window.
4. Observe the bottom line of the scroll bar.

Actual result

The bottom line of the scroll bar remains visible at certain zoom levels after scrolling to the bottom of the modal window.

Expected result

The bottom line of the scroll bar shouldn't be visible when the user has scrolled to the bottom of the modal window, regardless of the browser's zoom level.

Environment

• UUI version: 5.11.0
• Browser name: Chrome, FF
• Operating System: Mac, Win