feat(studio): add styled Tooltip component to tabs and panels

Create a Tooltip component with styled popover (dark bg, border,
shadow) that appears on hover with a 400ms delay. Applied to:
- Left sidebar tabs: Code, Comps, Assets, Catalog
- Right panel tabs: Design, Layers, Motion, Renders

Replaces native title attributes with proper styled tooltips.

packages/studio/src/components/StudioRightPanel.tsx

@@ -1,3 +1,4 @@
+import { Tooltip } from "./ui";
 import { PropertyPanel } from "./editor/PropertyPanel";
 import { MotionPanel } from "./editor/MotionPanel";
 import { LayersPanel } from "./editor/LayersPanel";
@@ -106,58 +107,62 @@ export function StudioRightPanel({
             <div className="flex items-center gap-1 border-b border-neutral-800 px-3 py-2">
               {STUDIO_INSPECTOR_PANELS_ENABLED && (
                 <>
-                  <button
-                    type="button"
-                    onClick={() => setRightPanelTab("design")}
-                    title="Design"
-                    className={`h-8 rounded-xl px-3 text-[11px] font-medium transition-colors ${
-                      rightPanelTab === "design"
-                        ? "bg-neutral-800 text-white"
-                        : "text-neutral-500 hover:bg-neutral-800/70 hover:text-neutral-200"
-                    }`}
-                  >
-                    Design
-                  </button>
-                  <button
-                    type="button"
-                    onClick={() => setRightPanelTab("layers")}
-                    title="Layers"
-                    className={`h-8 rounded-xl px-3 text-[11px] font-medium transition-colors ${
-                      rightPanelTab === "layers"
-                        ? "bg-neutral-800 text-white"
-                        : "text-neutral-500 hover:bg-neutral-800/70 hover:text-neutral-200"
-                    }`}
-                  >
-                    Layers
-                  </button>
-                  {STUDIO_MOTION_PANEL_ENABLED && (
+                  <Tooltip label="Element styles and properties" side="bottom">
                     <button
                       type="button"
-                      onClick={() => setRightPanelTab("motion")}
-                      title="Motion"
+                      onClick={() => setRightPanelTab("design")}
                       className={`h-8 rounded-xl px-3 text-[11px] font-medium transition-colors ${
-                        rightPanelTab === "motion"
+                        rightPanelTab === "design"
                           ? "bg-neutral-800 text-white"
                           : "text-neutral-500 hover:bg-neutral-800/70 hover:text-neutral-200"
                       }`}
                     >
-                      Motion
+                      Design
                     </button>
+                  </Tooltip>
+                  <Tooltip label="Composition layer stack" side="bottom">
+                    <button
+                      type="button"
+                      onClick={() => setRightPanelTab("layers")}
+                      className={`h-8 rounded-xl px-3 text-[11px] font-medium transition-colors ${
+                        rightPanelTab === "layers"
+                          ? "bg-neutral-800 text-white"
+                          : "text-neutral-500 hover:bg-neutral-800/70 hover:text-neutral-200"
+                      }`}
+                    >
+                      Layers
+                    </button>
+                  </Tooltip>
+                  {STUDIO_MOTION_PANEL_ENABLED && (
+                    <Tooltip label="Animation and motion" side="bottom">
+                      <button
+                        type="button"
+                        onClick={() => setRightPanelTab("motion")}
+                        className={`h-8 rounded-xl px-3 text-[11px] font-medium transition-colors ${
+                          rightPanelTab === "motion"
+                            ? "bg-neutral-800 text-white"
+                            : "text-neutral-500 hover:bg-neutral-800/70 hover:text-neutral-200"
+                        }`}
+                      >
+                        Motion
+                      </button>
+                    </Tooltip>
                   )}
                 </>
               )}
-              <button
-                type="button"
-                onClick={() => setRightPanelTab("renders")}
-                title="Renders"
-                className={`h-8 rounded-xl px-3 text-[11px] font-medium transition-colors ${
-                  rightPanelTab === "renders"
-                    ? "bg-neutral-800 text-white"
-                    : "text-neutral-500 hover:bg-neutral-800/70 hover:text-neutral-200"
-                }`}
-              >
-                {renderJobs.length > 0 ? `Renders (${renderJobs.length})` : "Renders"}
-              </button>
+              <Tooltip label="Render queue and exports" side="bottom">
+                <button
+                  type="button"
+                  onClick={() => setRightPanelTab("renders")}
+                  className={`h-8 rounded-xl px-3 text-[11px] font-medium transition-colors ${
+                    rightPanelTab === "renders"
+                      ? "bg-neutral-800 text-white"
+                      : "text-neutral-500 hover:bg-neutral-800/70 hover:text-neutral-200"
+                  }`}
+                >
+                  {renderJobs.length > 0 ? `Renders (${renderJobs.length})` : "Renders"}
+                </button>
+              </Tooltip>
             </div>
             <div className="min-h-0 flex-1">
               {rightPanelTab === "block-params" && activeBlockParams ? (

packages/studio/src/components/sidebar/LeftSidebar.tsx

@@ -13,6 +13,7 @@ import { trackStudioEvent } from "../../utils/studioTelemetry";
 import { BlocksTab, type BlockPreviewInfo } from "./BlocksTab";
 import { FileTree } from "../editor/FileTree";
 import { STUDIO_BLOCKS_PANEL_ENABLED } from "../editor/manualEditingAvailability";
+import { Tooltip } from "../ui";
 
 export type SidebarTab = "compositions" | "assets" | "code" | "blocks";
 
@@ -124,55 +125,59 @@ export const LeftSidebar = memo(
                       : "1fr 1fr 1fr",
                   }}
                 >
-                  <button
-                    type="button"
-                    onClick={() => selectTab("code")}
-                    title="Source code editor"
-                    className={`rounded-[14px] px-1.5 py-2 text-[10px] font-semibold truncate transition-all ${
-                      tab === "code"
-                        ? "bg-neutral-800 text-white"
-                        : "text-neutral-500 hover:text-neutral-200"
-                    }`}
-                  >
-                    Code
-                  </button>
-                  <button
-                    type="button"
-                    onClick={() => selectTab("compositions")}
-                    title="Composition layers and sub-compositions"
-                    className={`rounded-[14px] px-1.5 py-2 text-[10px] font-semibold truncate transition-all ${
-                      tab === "compositions"
-                        ? "bg-neutral-800 text-white"
-                        : "text-neutral-500 hover:text-neutral-200"
-                    }`}
-                  >
-                    Comps
-                  </button>
-                  <button
-                    type="button"
-                    onClick={() => selectTab("assets")}
-                    title="Media assets — videos, images, audio, fonts"
-                    className={`rounded-[14px] px-1.5 py-2 text-[10px] font-semibold truncate transition-all ${
-                      tab === "assets"
-                        ? "bg-neutral-800 text-white"
-                        : "text-neutral-500 hover:text-neutral-200"
-                    }`}
-                  >
-                    Assets
-                  </button>
-                  {STUDIO_BLOCKS_PANEL_ENABLED && (
+                  <Tooltip label="Source code editor" side="bottom">
                     <button
                       type="button"
-                      onClick={() => selectTab("blocks")}
-                      title="Browse blocks, components, and templates from the registry"
+                      onClick={() => selectTab("code")}
                       className={`rounded-[14px] px-1.5 py-2 text-[10px] font-semibold truncate transition-all ${
-                        tab === "blocks"
+                        tab === "code"
                           ? "bg-neutral-800 text-white"
                           : "text-neutral-500 hover:text-neutral-200"
                       }`}
                     >
-                      Catalog
+                      Code
                     </button>
+                  </Tooltip>
+                  <Tooltip label="Compositions and sub-compositions" side="bottom">
+                    <button
+                      type="button"
+                      onClick={() => selectTab("compositions")}
+                      className={`rounded-[14px] px-1.5 py-2 text-[10px] font-semibold truncate transition-all ${
+                        tab === "compositions"
+                          ? "bg-neutral-800 text-white"
+                          : "text-neutral-500 hover:text-neutral-200"
+                      }`}
+                    >
+                      Comps
+                    </button>
+                  </Tooltip>
+                  <Tooltip label="Videos, images, audio, fonts" side="bottom">
+                    <button
+                      type="button"
+                      onClick={() => selectTab("assets")}
+                      className={`rounded-[14px] px-1.5 py-2 text-[10px] font-semibold truncate transition-all ${
+                        tab === "assets"
+                          ? "bg-neutral-800 text-white"
+                          : "text-neutral-500 hover:text-neutral-200"
+                      }`}
+                    >
+                      Assets
+                    </button>
+                  </Tooltip>
+                  {STUDIO_BLOCKS_PANEL_ENABLED && (
+                    <Tooltip label="Browse blocks and components" side="bottom">
+                      <button
+                        type="button"
+                        onClick={() => selectTab("blocks")}
+                        className={`rounded-[14px] px-1.5 py-2 text-[10px] font-semibold truncate transition-all ${
+                          tab === "blocks"
+                            ? "bg-neutral-800 text-white"
+                            : "text-neutral-500 hover:text-neutral-200"
+                        }`}
+                      >
+                        Catalog
+                      </button>
+                    </Tooltip>
                   )}
                 </div>
                 {onToggleCollapse && (

packages/studio/src/components/ui/Tooltip.tsx

@@ -0,0 +1,61 @@
+import { useState, useRef, useCallback, type ReactNode } from "react";
+import { createPortal } from "react-dom";
+
+interface TooltipProps {
+  label: string;
+  children: ReactNode;
+  delay?: number;
+  side?: "top" | "bottom";
+}
+
+export function Tooltip({ label, children, delay = 400, side = "top" }: TooltipProps) {
+  const [visible, setVisible] = useState(false);
+  const [pos, setPos] = useState({ x: 0, y: 0 });
+  const timerRef = useRef<ReturnType<typeof setTimeout> | null>(null);
+  const triggerRef = useRef<HTMLSpanElement>(null);
+
+  const show = useCallback(() => {
+    timerRef.current = setTimeout(() => {
+      const el = triggerRef.current;
+      if (!el) return;
+      const rect = el.getBoundingClientRect();
+      setPos({
+        x: rect.left + rect.width / 2,
+        y: side === "top" ? rect.top - 6 : rect.bottom + 6,
+      });
+      setVisible(true);
+    }, delay);
+  }, [delay, side]);
+
+  const hide = useCallback(() => {
+    if (timerRef.current) {
+      clearTimeout(timerRef.current);
+      timerRef.current = null;
+    }
+    setVisible(false);
+  }, []);
+
+  return (
+    <>
+      <span ref={triggerRef} onPointerEnter={show} onPointerLeave={hide} className="contents">
+        {children}
+      </span>
+      {visible &&
+        createPortal(
+          <div
+            className="fixed z-[200] pointer-events-none"
+            style={{
+              left: pos.x,
+              top: pos.y,
+              transform: side === "top" ? "translate(-50%, -100%)" : "translate(-50%, 0)",
+            }}
+          >
+            <div className="px-2 py-1 rounded-md bg-neutral-800 border border-neutral-700/50 text-[10px] font-medium text-neutral-200 whitespace-nowrap shadow-lg">
+              {label}
+            </div>
+          </div>,
+          document.body,
+        )}
+    </>
+  );
+}

packages/studio/src/components/ui/index.ts

@@ -2,3 +2,4 @@
 export { Button, IconButton } from "./Button";
 export { HyperframesLoader, StatusFrame } from "./HyperframesLoader";
 export type { HyperframesLoaderProps } from "./HyperframesLoader";
+export { Tooltip } from "./Tooltip";