Problems:
- Vertical Tabs layout is too densed, which is especially conspicuous when hovering a tab above or below the active tab.
- New Tab (+) button is kinda "floating" out of place, visually unrelated to anything that happens in sidebar.
Proposed solutions:
- Add a 4px top marign on each tab
- Make a New Tab button look like tabs themselves
This way, it should be easier to scan and click tabs, and with + button labeled, it should be clear and intuitive what will happen on click. It's also more beautiful to look at.