1 files changed, 13 insertions, 55 deletions

diff --git a/apps/web/src/components/editor/timeline/timeline-scroll-sync.tsx b/apps/web/src/components/editor/timeline/timeline-scroll-sync.tsx
index 2318f977..473c6f3e 100644
--- a/apps/web/src/components/editor/timeline/timeline-scroll-sync.tsx
+++ b/apps/web/src/components/editor/timeline/timeline-scroll-sync.tsx
@@ -3,20 +3,16 @@ import { useEffect, useRef } from "react";
 export interface TimelineScrollSyncProps {
   rulerScrollRef: React.RefObject<HTMLDivElement>;
   tracksScrollRef: React.RefObject<HTMLDivElement>;
-  trackLabelsScrollRef: React.RefObject<HTMLDivElement>;
 }
 
 export function useTimelineScrollSync({
   rulerScrollRef,
   tracksScrollRef,
-  trackLabelsScrollRef,
 }: TimelineScrollSyncProps) {
   const isUpdatingRef = useRef(false);
-  const lastRulerSync = useRef(0);
-  const lastTracksSync = useRef(0);
-  const lastVerticalSync = useRef(0);
+  const lastSyncRef = useRef(0);
 
-  // --- Scroll synchronization effect ---
+  // --- Horizontal scroll synchronization between ruler and tracks ---
   useEffect(() => {
     const rulerViewport = rulerScrollRef.current?.querySelector(
       "[data-radix-scroll-area-viewport]"
@@ -24,76 +20,38 @@ export function useTimelineScrollSync({
     const tracksViewport = tracksScrollRef.current?.querySelector(
       "[data-radix-scroll-area-viewport]"
     ) as HTMLElement;
-    const trackLabelsViewport = trackLabelsScrollRef.current?.querySelector(
-      "[data-radix-scroll-area-viewport]"
-    ) as HTMLElement;
 
     if (!rulerViewport || !tracksViewport) return;
 
-    // Horizontal scroll synchronization between ruler and tracks
+    // Throttled scroll handlers for better performance
     const handleRulerScroll = () => {
       const now = Date.now();
-      if (isUpdatingRef.current || now - lastRulerSync.current < 16) return;
-      lastRulerSync.current = now;
+      if (isUpdatingRef.current || now - lastSyncRef.current < 16) return; // 60fps throttling
+      lastSyncRef.current = now;
+
       isUpdatingRef.current = true;
       tracksViewport.scrollLeft = rulerViewport.scrollLeft;
       isUpdatingRef.current = false;
     };
+
     const handleTracksScroll = () => {
       const now = Date.now();
-      if (isUpdatingRef.current || now - lastTracksSync.current < 16) return;
-      lastTracksSync.current = now;
+      if (isUpdatingRef.current || now - lastSyncRef.current < 16) return; // 60fps throttling
+      lastSyncRef.current = now;
+
       isUpdatingRef.current = true;
       rulerViewport.scrollLeft = tracksViewport.scrollLeft;
       isUpdatingRef.current = false;
     };
 
-    rulerViewport.addEventListener("scroll", handleRulerScroll);
-    tracksViewport.addEventListener("scroll", handleTracksScroll);
-
-    // Vertical scroll synchronization between track labels and tracks content
-    if (trackLabelsViewport) {
-      const handleTrackLabelsScroll = () => {
-        const now = Date.now();
-        if (isUpdatingRef.current || now - lastVerticalSync.current < 16)
-          return;
-        lastVerticalSync.current = now;
-        isUpdatingRef.current = true;
-        tracksViewport.scrollTop = trackLabelsViewport.scrollTop;
-        isUpdatingRef.current = false;
-      };
-      const handleTracksVerticalScroll = () => {
-        const now = Date.now();
-        if (isUpdatingRef.current || now - lastVerticalSync.current < 16)
-          return;
-        lastVerticalSync.current = now;
-        isUpdatingRef.current = true;
-        trackLabelsViewport.scrollTop = tracksViewport.scrollTop;
-        isUpdatingRef.current = false;
-      };
-
-      trackLabelsViewport.addEventListener("scroll", handleTrackLabelsScroll);
-      tracksViewport.addEventListener("scroll", handleTracksVerticalScroll);
-
-      return () => {
-        rulerViewport.removeEventListener("scroll", handleRulerScroll);
-        tracksViewport.removeEventListener("scroll", handleTracksScroll);
-        trackLabelsViewport.removeEventListener(
-          "scroll",
-          handleTrackLabelsScroll
-        );
-        tracksViewport.removeEventListener(
-          "scroll",
-          handleTracksVerticalScroll
-        );
-      };
-    }
+    rulerViewport.addEventListener("scroll", handleRulerScroll, { passive: true });
+    tracksViewport.addEventListener("scroll", handleTracksScroll, { passive: true });
 
     return () => {
       rulerViewport.removeEventListener("scroll", handleRulerScroll);
       tracksViewport.removeEventListener("scroll", handleTracksScroll);
     };
-  }, []);
+  }, [rulerScrollRef, tracksScrollRef]);
 
   return null;
 }