[Code Evaluation] The Play button becomes oversized in small browser window

[Nina-1210]

Describe the bug
When the browser window is resized to a smaller width, the Play button in the Code Evaluation tool scales incorrectly and becomes disproportionately large compared to surrounding UI elements.

Steps to reproduce the behavior:

1. Navigate to MakeCode Code Evaluation.
2. Enter a Shared Project link, e.g. https://makecode.microbit.org/S49237-69514-96142-91189.
3. Resize the browser window to a small width.
4. Observe the Play button in the bottom-right corner.

Actual behavior
The Play button becomes oversized when the window width is reduced, resulting in an inconsistent UI layout.

Expected behavior
The Play button should scale appropriately and maintain a consistent size, layout, and visual alignment with other controls regardless of window size.

Screenshots

Additional context
1.OS: Windows 11 25H2
2.Browser: Chrome, Edge, and Firefox
3.makecode.microbit.org version: 8.1.30
4.Microsoft MakeCode version: 12.3.26