With these settings I managed to hide all the tabs.
First I set the position of the tabs to the right in `Preferences > Interface > Notebook tabs > Tab Position > Message Window`
Then I added a negative margin as follows:
```css #notebook_info { padding: 1px; padding-left: 5px; margin-right: -56px; font-size: 0.1em; } ```
The left padding is not necessary but it looks better to me, here is a pic:
