Add Models button has uneven horizontal padding

## Description

The **Add Models** button in the Manage Models modal has uneven left and right padding.

## Steps to reproduce

1. Open the Manage Models modal.
2. Locate the **Add Models** button.
3. Compare the button padding on its left and right sides.

## Expected behavior

The button has equal left and right padding.

## Actual behavior

The button has uneven left and right padding.