Gotcha: Forgetting `flex` on the Parent Container

Problem: Parent LACKS `flex` (Gotcha!)

Child Item A

Child Item B

Child Item C

Gotcha: The child items (A, B, C) stack vertically because their direct parent `div` (the one with the red border) does not have the `flex` utility class.

Solution: Parent HAS `flex`

Child Item A

Child Item B

Child Item C

Corrected: By adding `flex` to the parent `div` (the one with the green border), the child items now correctly line up horizontally.