Shared layout tooltips
In a tight control cluster, separate tooltips feel like doors slamming. One shared tooltip keeps the bubble alive and lets label text hand off left or right.
Grouped icon buttons belong to one composition. Give them a single Base UI tooltip via Tooltip.createHandle — every trigger passes a payload, and one Tooltip.Root renders the active label. The positioner and popup can then transition top/left and width/height as the pointer moves across the group.
Wrap the label in Tooltip.Viewport to enable location-aware content animation. data-activation-direction reports whether the new trigger sits left or right of the previous one; fade the outgoing text out toward the opposite side and the incoming text in from the travel direction.
Toggle Shared tooltip off to feel the naive pattern: each control owns its own root, so the bubble dismisses and reopens. Turn it on and sweep across Bold → Italic → Underline → Link — one surface, shared layout motion, directional text. The Delete control beside the group stays on its own root either way — only clustered actions should share a handle.