# Tab Flicker Fix

## Issue
The user reports a flicker when clicking a tab before it becomes active.

## Diagnosis
The current implementation of the active tab style uses `borderBottom: isActive ? 2 : 0`. This causes a layout shift (height change or content displacement) of 2px whenever the active state changes. This visual jump is perceived as a flicker.

## Solution
Update the styling to maintain a constant border width but change the color.
-   Change `borderBottom` to always be `2`.
-   Change `borderColor` to be `'primary.main'` when active and `'transparent'` when inactive.

## Plan
1.  Modify `src/frontend/src/components/TabsBar.tsx`.
2.  Update `SortableTab` styles.