How does water get to the leaves in the tops of the tallest trees against the force of gravity

Capillary Action.

Adhesion is when water sticks to other objects. So the water sticks to the vascular tissue tube walls.

Cohesion is when water sticks to itself. So the water pulls itself along the center of those vascular tissue tubes. Therefore define gravity as more and more molecules get pulled up then evaporated over and over again.

Simplly in short words:

water gets to the leave in the top of the tallest trees against the force of gravity due to the cause of cohesive force of water by the vascular bundles.