diff --git a/app.js b/app.js
index 23237d1..d5f55db 100644
--- a/app.js
+++ b/app.js
@@ -6280,6 +6280,7 @@ function ensureFont(name) {
 
 /* ── Main loop ── */
 let lastTs = null;
+let playheadPx = -1;
 function loop(ts) {
   if (lastTs == null) lastTs = ts;
   const dt = Math.min(0.1, (ts - lastTs) / 1000);
@@ -6305,7 +6306,11 @@ function loop(ts) {
     drawFrame();
   }
   if (state.dirtyTimeline) rebuildClips();
-  els.playhead.style.left = state.time * state.pps + "px";
+  const phX = Math.round(state.time * state.pps);
+  if (phX !== playheadPx) {
+    playheadPx = phX;
+    els.playhead.style.left = phX + "px";
+  }
   drawRuler();
   updateSafeOverlay();
   updateKfGraphs();
diff --git a/style.css b/style.css
index bc33913..cba587f 100644
--- a/style.css
+++ b/style.css
@@ -1542,6 +1542,7 @@ input[type=range] {
 
 .timeline-scroll {
   flex: 1;
+  min-height: 0;
   overflow-x: auto;
   overflow-y: auto;
   position: relative;
@@ -1560,6 +1561,9 @@ input[type=range] {
 
 .tracks-content {
   position: relative;
+  /* clip so abspos playhead `left` cannot grow the scroller's overflow */
+  overflow: clip;
+  overflow-clip-margin: 8px;
 }
 .work-dim {
   position: absolute;
@@ -1876,6 +1880,7 @@ body.track-size-s .clip .clip-kf-n {
   background: #ff4d6a;
   z-index: 4;
   pointer-events: none;
+  contain: layout;
 }
 
 .playhead-cap {