Top slider should have a smooth animation when switching between Placement / Internship / External blog tabs

Description:
When switching between the Placement, Internship, and External blog tabs, the top slider/indicator jumps to the new position instantly with no transition.

Expected behavior:
The top slider indicator should smoothly animate (slide left/right) when switching tabs.

Start by locating the screen that renders the Placement, Internship, and External blog tabs, then inspect how the top slider indicator changes position. Confirm the current behavior and identify the relevant widget before making the indicator transition smoothly; done means switching between all three tabs visibly animates the indicator.

Written by the indexing model from the issue text.