[segment explorer] fix content overflow styling (#81649)
* The bottom reset button should cover the content
* No need for transparent button background
| After | Before |
|:--|:--|
| <video src="https://github.com/user-attachments/assets/598a6474-315a-4ed5-819b-dd49306125ef"> | <video src="https://github.com/user-attachments/assets/9d7ba02c-033e-43b7-a65c-6764e903e10e"> |
