Search and reasoning toggles not accessible on mobile (vertical viewport)

On mobile devices in portrait/vertical orientation, the search and reasoning toggle buttons in the chat input area are positioned off-screen or hidden behind the viewport edge, making them impossible to interact with.

Steps to Reproduce:

1. Open T3 Chat on a mobile device (or resize browser to a vertical/ mobile viewport)

2. Look at the chat input area

3. Attempt to toggle the search or reasoning options